OSCC Flashcards
Where does the word “tumour” originate from?
latin - swelling
What is the general nomenclature for benign tumours?
-oma to the cell type the neoplasm arises from
What is the exception to the normal rule of naming benign tumours?
epithelial neoplasms
How are benign epithelial neoplasms classified?
on their microscopic or macroscopic patterns
Adenoma
benign gland patterned epithelial neoplasm
Papilloma
benign epithelial neoplasm producing microscopic or macroscopic fingerlike fronds
How are malignant epithelial origin neoplasms named?
-carcinoma
How are malignant CT neoplasms named?
-sarcoma
How are malignant epithelial neoplasms classified?
on their microscopic or macroscopic pattern
What do the neoplastic cells resemble in squamous cell carcinoma?
stratified squamous epithelium
What are the three exceptions in malignant nomenclature?
lymphoma, mesothelioma, melanoma
Growth type of benign tumours
expansive
Growth type of malignant tumours
infiltrating
Growth speed of benign tumours
usually slow
Growth speed of malignant tumours
usually rapid
Do benign tumours often stabilise?
yes
Do malignant tumours often stabilise?
no it would be exceptional
Structure of benign tumours
typical
Structure of malignant tumours
atypical (dedifferentiation - anaplasia)
Mitoses in benign tumours
rare and typical
Mitoses in malignant tumours
numerous and atypical
Evolution of benign tumours
local
Evolution of malignant tumours
local and general
Local consequences of benign tumours
variable - compressions
3 local severe consequences of malignant tumours
infiltration, destruction, necrosis
General consequences of benign tumours
none unless secretory tumours/particular sites
In what phase are the general consequences of malignant tumours constant and severe?
generalisation phase
Which type of tumour is always fatal without treatment?
malignant
Do benign tumours tend to recur?
no
OSCC gender ratio
M 2.22:1 F
Three most common oral cancers
OSCC, NHL, mucoepidermoid carcinoma
Which continent has a high prevalence of oral cancer?
Asia
Black patients and oral cancer
detected later and greater mortality
what percentage of cancers are oral?
2%
what % of oral cancer is in over 55s?
78%
Most common oral cancer site
tonsils
2nd most common oral cancer site
tongue
3rd most common oral cancer site
base of tongue
where does OSCC originate from?
oral keratinocytes
what % of oral cancers are SCC?
over 90%
3 most common sites for OSCC?
tongue, FOM, gingiva
In countries where betel quid chewing is practiced, where are the 2 most common OSCC sites?
buccal mucosa and gingiva
How is early stage OSCC usually detected and why?
incidentally as tends to be asymptomatic
What are the 8 subtypes of OSCC?
- verrucous carcinoma
- basal SCC
- papillary SCC
- spindle cell SCC
- Adenosquamous carcinoma
- lymph-epithelial carcinoma
- acantholytic SCC
- carcinoma cuniculatum
Which subtypes of OSCC have a better prognosis?
verrucous carcinoma
papillary SCC
which subtypes of OSCC have a worse prognosis?
spindle cell SCC
adenosquamous carcinoma
which 3 subtypes have an exophytic verruco-papillary component?
verrucous carcinoma
carcinoma cuniculatum
papillary SCC
What are the 4 clinical appearances of OSCC?
OPMDs
ulceration
speckled
exophytic growth
OSCC appearance - OPMDs
flat/slightly raised red/white/mixed exophytic lesions
may get changes in surface texture (smooth, granular, rough, crusted)
OSCC appearance - ulceration
solitary lesion that is not healing/responding to conservative management
usually presents with irregular and indurated margins
OSCC appearance - speckled
ill-defined mixed white-red lesions with granular aspects
OSCC appearance - exophytic growth
irregular overgrowth with a smooth or verrucopapillary (verrucous carcinoma) surface above normal mucosa
Late stage OSCC - what is the usual cause of pain?
ulceration
Late stage OSCC - what leads to trismus?
OSCC of buccal mucosa and involvement of the infra temporal fossa
Late stage OSCC - FOM symptoms
restriction of tongue mobility
progressive difficulty in mastication and speech
drooling of saliva
Late stage OSCC - gingiva
excessive mobility of involved teeth due to involvement of periosteum and possible spread to bone
Late stage OSCC - tongue base
sensation of fullness in throat dysphagia sensation of a lump in neck/throat voice changes ear pain
What 3 parts of the diagnostic pathway do you need for staging and grading?
pt history and exam
histopathology and clinical adjuncts
radiologic imaging
2 predictors of prognosis
staging and grading
Grading
cytologic differentiation of the cells - how much the cancer cells look like healthy cells under a microscope
Staging
where has the cancer spread?
5 morphologic features considered in grading
degree of keratinisation nuclear polymorphism number of mitoses pattern of invasion host response
Which morphologic feature is excluded from the Bryne grading system?
number of mitoses
what is the ideal pattern of invasion of a tumour?
pushing, well-delineated, infiltrating borders
Grade X
differentiation can’t be assessed
Grade 1
well-differentiated
Grade 2
moderately differentiated
Grade 3
poorly differentiated
Grade 4
undifferentiated or anaplastic
Grades
X, 1, 2, 3, 4
What does a lower grade mean?
better prognosis
What does the grade predict?
how quickly the cancer will spread
What does TNM staging stand for?
Tumour, Node, Metastasis
TNM staging - T stages
T0-4
TNM staging - what does T describe?
size (cm) and location, how much the tumour has grown into nearby tissues
TNM staging - N stages
N0-3
TNM staging - what does N describe?
whether the cancer has spread to lymph nodes - regional or distant
TNM staging - M stages
M0 or M1
TNM staging - what does M describe?
whether cancer has spread to other parts of the body - distant metastasis
What does the 8th edition cancer staging not include?
non-epithelial tumours
what does T incorporate in 8th edition cancer staging?
DOI
what does N incorporate in 8th edition cancer staging?
ENE
Tumour Thickness
mucosal surface of tumour to deepest point of tissue invasion in a perpendicular fashion
Depth of Invasion
level of basement membrane adjacent to normal mucosa to deepest point of tumour invasion
What DOI is associated with a significantly increased risk of recurrence and nodal metastasis?
> 10mm
When should elective neck dissection be considered?
for tumours <5mm deep
ENE
extension of metastatic cells through the nodal capsule into the perinodal tissue
what is the advantage of 8th edition cancer staging?
leads to identification if OSCC pts with a worse prognosis who might benefit from an improved post-op tx strategy
give some examples of where oral cancer can metastasise to
anywhere - lung, heart, vertebra, chest wall
What do you do before an imaging assessment?
establish the primary site and any neck metastasis clinically
have histological diagnosis
What is the role of radiology?
accurately stage the full extent and distant spread of disease with TNM system
What are the focus areas for imaging?
local extent of primary tumour
spread to loco regional cervical lymph nodes
detection of metastatic disease precluding cure and synchronous primary tumours of lung/upper aero-digestive tract
What is the main form of imaging used to detect the primary tumour?
CT
what is CT used for?
detecting primary tumour
local bone infiltration
multi-detector CT (MDCT)
precisely determine boundaries of tumour
contrast-enhanced CT (CECT)
accurately determine LN metastases
what can’t CT differentiate between?
recurrences, surgical scars and adverse reactions after radiation therapy
Give a form of imaging using ionising radiation
CT
give 2 examples of imaging without ionising radiation
MRI, US
give a form of functional imaging
Positron Emission Tomography combined with CT (PET-CT)
what can MRI determine the involvement of?
local STs, bone marrow, bones, vessels, nerves
local LN and distant metastases
what is MRI better than CT/CBCT for?
assessment of STs
2 advantages of US
cheap and non-invasive
3 uses of US
evaluate superficial lesions
evaluate LNs
guide FNAB
what can colour doppler US be used for and what is the advantage of this?
to determine the type of blood vascularity in a lesion
often increases the specificity of diagnosis
what is the advantage of PET-CT over CT or MRI?
may detect malignancy in structures which appear normal or are difficult to assess on CT/MRI e.g. small vol LN metastases
give 3 uses of PET-CT
look for the primary tumour site when metastases are found earlier (CUP)
detect recurrence of primary tumours
detect distant metastases of primary tumours
when is PET-CT recommended?
advanced cancer stages
8th edition cancer staging - 4 subsections
definition of primary tumour (T)
definition of regional LN (N, pN)
definition of regional LN (N, cN)
definition of distant metastases (M)
8th edition cancer staging - T stages
TX Tis T1 T2 T3 T4a T4b
8th edition cancer staging - TX
primary tumour can’t be assessed
8th edition cancer staging - Tis
carcinoma in situ
8th edition cancer staging - T1
< or = 2cm
DOI < or = 5mm
8th edition cancer staging - T2
25mm
8th edition cancer staging - T3
210mm
OR
>4cm, DOI <=10mm
8th edition cancer staging - T4a
moderately advanced local disease
>4cm, DOI >10mm
OR
invaded adjacent structures only (superficial erosion of bone/socket alone by a gingival primary is not T4)
8th edition cancer staging - T4b
v advanced local disease - tumour invades masticator space, pterygoid plates, or skull base and/or encases ICA
8th edition cancer staging - NX
regional lymph nodes can’t be assessed
8th edition cancer staging - N0
no regional LN metastasis
8th edition cancer staging - N1
1 ipsilateral
<=3cm
ENE -
8th edition cancer staging - N2a
single ipsilateral, 3
8th edition cancer staging - N2b
multiple ipsilateral <=6cm, ENE -
8th edition cancer staging - N2c
bilateral/contralateral, <=6cm, ENE -
8th edition cancer staging - N3a
> 6cm, ENE -
8th edition cancer staging - N3b
any nodes and clinically overt ENE+
OR pN3b: 1 ipsilateral >3cm, ENE+ or multiple ipsilateral/contralateral/bilateral ENE+ or single contralateral, any size, ENE+
8th edition cancer staging - cM0
no distant metastasis
8th edition cancer staging - cM1
distant metastasis
8th edition cancer staging - pM1
distant metastasis, microscopically confirmed
8th edition cancer staging - what does U or L for N category mean?
indicates metastasis above the lower border of the cricoid (U) or below (L)
8th edition cancer staging - prognostic staging groups
0 1 2 3 4a 4b 4c
8th edition cancer staging - stage 0
Tis
N0
M0
8th edition cancer staging - stage 1
T1
N0
M0
8th edition cancer staging - stage 2
T2
N0
M0
8th edition cancer staging - stage 3
T3 N0 M0
or
T1/2/3 N1 M0
8th edition cancer staging - stage 4a
T4a N0/1 M0
or
T1/2/3/4a N2 M0
8th edition cancer staging - stage 4b
any T N3 M0
or
T4b any N M0
8th edition cancer staging - stage 4c
any T
any N
M1
how do involved LNs initially present?
soft
mobile
non-tender
how do involved LNs present at the advanced stage or in aggressive disease?
enlarged
firm/hard texture
usually non-tender fixation to adjacent tissue due to invasion of cells through the capsule
Lymph node levels
1a 1b 2a 2b 3 4 5a 5b 6 7
LN level 1a
submental
LN level 1b
submandibular
LN level 2a and b
upper jugular
LN level 3
mid jugular
LN level 4
lower jugular
LN level 5a and b
posterior triangle
LN level 6
anterior compartment
LN level 7
superior mediastinal
location of LN level 1a - submental
between anterior bodies of digastric muscles and hyoid bone
what do the submental (1a) nodes drain?
lower lip and chin
secondary drainage for anterior tongue
location of LN level 1b - submandibular
from U to L margin of submandibular gland
medial to mandible
lateral to posterior body of digastric muscle
what do the submandibular (1b) nodes drain?
oral cavity
lower nasal cavity
submandibular gland
location of LN level 2 - upper jugular
from underside of lateral process of C1 to hyoid
medial to SCM
lateral to scalene muscles
what is LN level 2 divided into a and b by?
posterior border of IJV
what do the upper jugular (2) nodes drain?
nasal cavity nasopharynx oropharynx larynx hypopharynx parotid gland secondary drainage for oral cavity
location of LN level 3 - mid jugular
from bottom of hyoid to bottom of cricoid cartilage
medial to SCM
lateral to scalene muscles
what do the mid jugular (3) nodes drain?
nasopharynx oral cavity oropharynx larynx hypopharynx
location of LN level 4 - lower jugular
from bottom of cricoid to 2cm above sternoclavicular joint
medial to SCM
lateral to scalene muscle
what do the lower jugular (4) nodes drain?
hypopharynx larynx thyroid cervical oesophagus distal drainage from higher cervical levels
location of LN level 5 a and b - posterior triangle
from hyoid to transverse cervical vessels
medial to tail of SCM
lateral to anterior border of trapezius
what do the posterior triangle (5) nodes drain?
nasopharynx
oropharynx
thyroid
posterior sack
location of LN level 6 - anterior compartment
from lower edge of hyoid to upper edge of sternal manubrium
between SCMs
what is LN level 6 divided into a and b by?
lower margin of cricoid cartilage
what does LN level 6 drain?
lower face tip of tongue FOM anterior neck hypopharynx thyroid larynx cervical oesophagus
location of LN level 7 - superior mediastinal
from superior edge of manubrium sterni to upper border of arch of aorta
between left CCA and right innominate artery
what do the superior mediastinal (7) nodes drain?
nasopharynx
soft palate
tonsillar fossa
posterior pharyngeal wall
Predominant lymph node levels for metastasis - buccal
1b
100%
Predominant lymph node levels for metastasis - gingival
1a/b
70%
Predominant lymph node levels for metastasis - retromolar
1b/2a
62-80%
Predominant lymph node levels for metastasis - maxillary
1b/2a
60-70%
Predominant lymph node levels for metastasis - soft palate
1/2a (55%)
but also 25% contralateral involvement
Predominant lymph node levels for metastasis - tongue
2b 8% 1/2a 75% 4 6-8% contralateral 6-12% more posterior = higher chance to involve the upper jugular and contralateral nodal metastasis, due to higher lymphatic interconnections posteriorly towards base of tongue
Predominant lymph node levels for metastasis - FOM
1/2a 75%
contralateral 8-10%
in OSCC pts, when are level 4 (lower jugular) nodes only usually involved?
when other neck levels are positive for metastases
what feature of the primary tumour gives a greater risk of bilateral cervical node spread?
the closer to the midline the primary is
which areas does oropharyngeal cancer include?
base of tongue inferior (anterior) surface of the soft palate and uvula anterior and posterior tonsillar pillars pharyngeal tonsils lateral and posterior pharyngeal walls
staging for OPC non-HPV mediated (p16-)
same categories for oral and lip SCC
- T, cN, pN, M, prognostic staging group
staging for HPV-mediated (p16+) OPC - T stages
T0 T1 T2 T3 T4
staging for HPV-mediated (p16+) OPC - T0
no primary identified (but identifiable neck node)
staging for HPV-mediated (p16+) OPC - T1
<=2cm
staging for HPV-mediated (p16+) OPC - T2
2
staging for HPV-mediated (p16+) OPC - T3
> 4cm
OR
extension to lingual surface of epiglottis
staging for HPV-mediated (p16+) OPC - T4
moderately advanced local disease
(tumour invades the larynx, extrinsic tongue muscles, medial pterygoid, hard palate or mandible or beyond (mucosal extension to lingual surface of epiglottis from primary tumours of the base of the tongue and vallecula does not constitute invasion of the larynx))
staging for HPV-mediated (p16+) OPC - cN stages
cNX cN0 cN1 cN2 cN3
staging for HPV-mediated (p16+) OPC - cNX
regional LNs cannot be assessed
staging for HPV-mediated (p16+) OPC - cN0
no regional LN metastasis
staging for HPV-mediated (p16+) OPC - cN1
> = 1 ipsilateral, less than or equal to 6cm
staging for HPV-mediated (p16+) OPC - cN2
contralateral or bilateral, less than or equal to 6cm
staging for HPV-mediated (p16+) OPC - cN2
LNs >6cm
staging for HPV-mediated (p16+) OPC - pN stages
pNX
pN0
pN1
pN2
staging for HPV-mediated (p16+) OPC - pNX
regional LNs cannot be assessed
staging for HPV-mediated (p16+) OPC - pN0
no regional LN metastasis
staging for HPV-mediated (p16+) OPC - pN1
less than or equal to 4 LNs
staging for HPV-mediated (p16+) OPC - pN2
> 4 LNs
staging for HPV-mediated (p16+) OPC - M stages
cM0
cM1
pM1
staging for HPV-mediated (p16+) OPC - cM0
no distant metastasis
staging for HPV-mediated (p16+) OPC - cM1
distant metastasis
staging for HPV-mediated (p16+) OPC - pM1
distant metastasis, microscopically confirmed
staging for HPV-mediated (p16+) OPC - cTNM prognostic staging group 1
T0/1/2
N0/1
M0
staging for HPV-mediated (p16+) OPC - cTNM prognostic staging group 2
T0/1/2. N2. M0
or
T3. N0/1/2. M0
staging for HPV-mediated (p16+) OPC - cTNM prognostic staging group 3
any T. N3. M0
or
T4. N0/1/2/3. M0
staging for HPV-mediated (p16+) OPC - cTNM prognostic staging group 4
any T
any N
M1
staging for HPV-mediated (p16+) OPC - pTNM prognostic staging group 1
T0/1/2
N0/1
M0
staging for HPV-mediated (p16+) OPC - pTNM prognostic staging group 2
T0/1/2. N2. M0
or
T3/4. N0/1. M0
staging for HPV-mediated (p16+) OPC - pTNM prognostic staging group 3
T3/4
N2
M0
staging for HPV-mediated (p16+) OPC - pTNM prognostic staging group 4
any T
any N
M1
three aspects of multimodal approach to treatment
surgery
chemo
radio
OSCC stage 1 and 2 tx
surgery or radio
OSCC stage 3 and 4 tx
concomitant radio/chemo (+surgery) better outcomes than radio (+surgery)
what are definitive radio, concurrent CRT and sequential therapy usually limited to?
pts who are
- medically inoperable
- unresectable disease
- resectable disease where surgical resection cannot be accomplished with acceptable long-term functional consequences
what is the goal of surgery?
completely resect the primary tumour and any neck deposit, wherever achievable, to prevent recurrence and conserve high survival rate
why is surgery preferred over radio for stage 1/2?
reduced morbidity
stage 3/4 surgery
complete resection of primary tumour and neck nodes
why is it important to ensure negative resection margins?
increased risk of treatment failure in patients with positive surgical margins
how do you check for negative margins?
specimen examined and microscopic margins checked
give 3 examples of surgical techniques
open resection
transoral robotic surgery (TORS)
transoral laser microsurgery (TLM)
give 2 contraindications to open resection
T4b - invasion of the masticator space, pterygoid plates, skull base or carotid encasement
pt perception of QOL
what is the reason behind using minimally invasive surgery: TORS, TLM?
it mat provide improved functional outcomes with minimal surgical morbidity and enhance the pathologic staging
how does TORS work?
surgeon distant from patient controlling robotic unit
indications for minimally invasive surgery
T1-2 tumours of oropharynx but only if surgeon has good oral access
contraindications for minimally invasive surgery
retrognathia
class 2 malocclusion
limited cervical extension
SP tumour - higher rate of rhinolalia, velopharyngeal insufficiency and nasopharyngeal reflux
advantages of minimally invasive surgery
no external incision no mandibulotomy or transmandibular access decreased immediate post-op toxicity shorter post-op hospitalisation time faster fct recovery enhanced visualisation - 3D+magnification of the field elimination of physiologic tremors movements can be scaled fatigue reduction training - teaching purposes
disadvantages of minimally invasive surgery
absence of tactile sensation - unable to feel tissue resistance or how tight a knot is
equipment size and weight
£££ - installation and annual maintenance
give the 4 types of neck dissection
comprehensive
selective
superselective
elective
comprehensive neck dissection
all LN levels of the neck are removed with/without 3 non-lymphatic structures (SCM, IJV, CN12)
selective neck dissection
not all LN levels are dissected
OSCC at least level 1-3
oropharyngeal SCC at least level 2-4
superselective neck dissection
dissection of only one or two contiguous LN levels to further decrease the morbidity of neck dissection
elective neck dissection
dissection of the appropriate nodal level, based on the risk of occult microscopic metastases
for OSCC what do you use to predict occult metastasis and guide neck dissection decision?
SLNB or DOI
what DOI is an accurate cut off value for performing an elective neck dissection in early stage OSCC?
DOI more than or equal to 4mm
what is a SLNB?
identifying and harvesting the initial node to which the primary tumour drains
high diagnostic accuracy
indications for a SLNB
to assess pts with biopsy-proven OSCC staged as early tumours with clinically (palpation) and radiologically (US, CT, MRI) N0 neck
assess bilateral N0 necks in primary tumours close to or crossing the midline
what can improve SLNB diagnostic sensitivity?
using immunohistochemistry
how does radiation therapy work?
uses high energy ionising radiation to disrupt the integrity of malignant cells through focal DNA damage, while doing as little harm as possible to normal cells
4 uses of radiation therapy
exclusive treatment of primary cancer
adjuvant therapy after surgery
adjuvant therapy before surgery
palliative therapy
radio - exclusive treatment of primary cancer
early stage cancer
unresectable/advanced in combination with chemo
radio - adjuvant therapy after surgery
+/- chemo to control positive neck nodes and/or killing remaining cancer cells in + margins
radio - adjuvant therapy before surgery
+/- chemo to shrink size of tumour
radio - palliative therapy
to control symptoms of advanced OSCC e.g. pain, bleeding, dysphagia, and problems caused by bone metastases, and to give pt a better QOL
types of radiotherapy
external beam radiotherapy
(internal) brachytherapy
how does EBRT work?
machine used to aim high energy rays/beams from outside the body into the tumour
focus the radiation on the exact location it needs to be, so normal tissues are affected as little as possible
normal treatment regime for EBRT
5 days a week for 6-7wks
2 examples of other EBRT schedules and their + and - s
hyperfractionation
accelerated fractionation
+may reduce the risk of cancer coming back in or near the place it started (local recurrence)
-tend to have more severe side effects
EBRT - hyperfractionation
total radiation dose in a larger number of doses e.g. 2 smaller doses per day
EBRT - accelerated fractionation
> or= 2 doses given each day so treatment completed faster
what is EBRT simulation technique for?
determine areas that will be radiated through a simulator
EBRT simulation technique procedure
supine on table, arms at sides, neck extended
immobilised by a thermoplastic head/shoulders mask to secure and gently hold head in place
head in neutral position
don’t swallow during scanning
scan to identify target volumes
mark pt with tattoos in tx fields so they can be set up each day with precision, while allowing pt to wash without obscuring tx fields
name some types of EBRT
intensity modulated (IMRT) 3D conformal RT (3D-CRT) image guided (IGRT) volumetric modulated arc therapy (VMAT/Rapid arc) intensity modulated proton therapy (IMPT) stereotactic radio surgery (SRS) stereotactic body RT (SBRT) intraoperative RT (IORT)
what is IMRT?
high precision RT that uses computer controlled linear accelerators to deliver precise radiation doses to a malignant tumour or specific areas within the tumour
IMRT - what is the dose to target usually proportional to?
estimated tumour burden
advantages of IMRT
higher doses to be focused on the tumour
spares organs at risk (OAR)
(more individualised tx)
internal radiation therapy (brachytherapy)
hollow catheters placed into/around the tumour during surgery
left in place for several days while pt stays in hospital
radioactive materials are put into tubes for a short time each day
small radioactive pellets (rice) put right into tumour. give off low levels of radioactivity for several weeks and over time lose their strength
pellets just left in place and rarely cause any problems
when do short term RT side effects occur?
visible during/immediately after RT and may last for 2-3weeks after tx
short term RT side effects
oral mucositis dental pain taste loss trismus (due to pain) odynophagia dysphagia candidiasis radiation dermatitis (RD) ORN
when do long term RT side effects occur?
visible several weeks after RT and may last for long time or even permanently after tx
long term RT side effects
salivary gland hypofct
trismus (muscle fibrosis)
extensive dentition breakdown due to radiation caries (RC)
ORN (can develop over months or years after completion of RT)
what is ORN?
irradiated bone becomes devitalised and exposed through the overlying skin or mucosa without healing for 3m, without recurrences of tumour
why is the mandible more affected by ORN?
only supplied by inferior alveolar artery, whereas maxilla supplied by anterior, middle and posterior superior alveolar arteries
ORN staging classification
no universally used one Marx Epstein et al Schwartz and Kagan Notani et al
what % of ORN cases develop within the first 3 years after radiotherapy?
70-94%
risk factors for ORN
hyperfractionated irradiation regimen
high total dose (6000-7000cGy)
literature suggests chemo and radio increases incidence
pre-irradiation and post-irradiation dental extractions
poor OH and PDD
tobacco and alcohol use
ORN conservative tx
improve OH antibiotics minimal surgical debridement hyperbaric 02 therapy medical management: pentoxifylline, tocopherol
ORN surgical tx
sequestrectomy
saucerisation
segmental resection and free flap reconstruction
what is chemotherapy?
a drug tx to kill fast growing cancer cells that multiply much more quickly than most cells in the body
indications for chemotherapy
- can use as the primary or sole tx for cancer
- adjuvant therapy after surgery (+/- radio) to kill any residual cancer cells
- adjuvant therapy before surgery (+/-radio) to shrink the size of the tumour
- palliative therapy to relieve S+S of advanced OSCC and give pt a better QOL
which gender may benefit more from chemo in CST?
women
3 types of chemotherapy
adjuvant
induction
concomitant
adjuvant chemo
given after surgery for reducing the incidence of distant metastatic recurrence
induction chemo
given before definitive tx (radio/surgery)
potentially reduce the risk of distant metastasis and the size of the primary tumour to improve loco regional control
concomitant chemo
given with surgery/radio to achieve radiosensitisation
give 2 indications for adjuvant chemotherapy
locally advanced disease HNSCC (stage 3-4b)
recurrent or metastatic HNSCC (stage 4c)
adjuvant chemo for locally advanced stage 3-4b
platinum based chemo and radio
- cisplatin, paclitaxel, 5-fluorouracil, carboplatin, cetuximab
adjuvant chemo for recurrent or metastatic stage 4c
cetuximab and platinum based chemo - cisplatin/carboplatin and 5-fluorouracil
or anti PD-1 immunotherapy plus chemo
- pembrolizumab and platinum and 5-fluorouracil
- nivolumab/pembrolizumab without chemo if pt has PD-LI+ recurrent or metastatic HNSCC
CRT
chemo given as a radiation sensitiser with the goal of reducing radiation resistance
chemo oral side effects
mucositis infection oral lichenoid reactions hyperpigmentations hyposalivation altered taste bleeding MRONJ SJS/TEN
treatment of early stage lip SCC
surgical resection definitive radio if surgery not feasible/pt unfit for surgery if deep (esp U lip) consider prophylactic selective neck dissection
post-surgical tx of early stage lip SCC
+ margins: reresection / radio
primary tumour with perineural/lymphovascular invasion: radio adjuvant
treatment of locally advanced lip SCC
surgical resection
definitive concurrent radio and chemo if pt unfit for surgery or surgery not feasible
often need neck dissection
post-surgical tx of locally advanced lip SCC
+ margins: reresection and adjuvant radio/chemoradio
perineural/vascular/lymphatic invasion: adjuvant radio
ENE: adjuvant chemo radio
treatment of early stage oral cavity SCC
resection
definitive radio if surgery not feasible - consider conformed techniques and brachytherapy
neck dissection depends on site, extent and thickness
- SLNB for DOI >3mm and most stage 2 lesions
post-op adjuvant therapy for early and locally advanced stage oral cavity SCC
1+ LN - discuss radio
ENE - systemic therapy and radio
close or + margin - reresection/ (radio); tx with concurrent chemo radio
invasion - consider radio
treatment of locally advanced stage oral cavity SCC
resection
definitive concurrent radio and chemo radio if can’t do surgery
ipsilateral/bilateral neck dissection
- if LNs involved, inc neck radio
treatment of early stage oropharyngeal SCC
clinical trials
definitive radio
surgical resection of primary tumour - minimally invasive techniques
consider elective nodal therapy
early stage and locally advanced oropharyngeal SCC post-op adjuvant therapy
CRT
if positive margins reresection then radio
treatment of locally advanced stage oropharyngeal SCC
concurrent CRT
resection (but usually reserved for smaller primary tumours)
radio for neck +/- dissection
risk factors for oral cancer
predisposing factors
genetic susceptibility
OPMDs
oral microbiome
predisposing factors for oral cancer
social - alcohol and tobacco (smoked and smokeless)
diet - low fruit and veg
physical agents - UV light, radiation
chemicals - env and occupational exposures (arsenic, benzene, asbestos)
what effect do combined predisposing factors have?
synergistic effect
give a way in which alcohol causes cancer
ethanol—ADH—>acetaldehyde—ALDH—>acetate(energy)
if too much alcohol drunk, body can’t process it fast enough so get build up of acetaldehyde - toxic and causes DNA damage
what infection in men may high alcohol lead to an increased risk of?
prevalent HPV infections
which foods may decrease the risk of oral cancer?
fruit and veg
fish and omega 3 fatty acids
which foods may increase the risk of oral cancer?
high consumption of processed meat
is there a significant association between total/red/white meat and risk of oral cancer?
no
do dietary supplements have the same effect on risk reduction of cancer as foods?
no
oral hygiene as a risk factor for oral cancer
may also be a prognostic factor
aids the carcinogenic potential of other known carcinogens e.g. tobacco and alcohol
- increases carcinogenicity of known carcinogens
oral microbiome as a risk factor for oral cancer
candida associated with increased risk
HPV
HPV manifestations
benign anogenital and cutaneous warts
respiratory papillomatosis
oral lesions
oral HPV manifestations
verruca - verruca vulgaris or common wart
condyloma - condyloma acuminatum
papilloma
not OPMDs
HPV genome structure - what 2 regions is it divided into?
E - early
L - late
HPV genome structure - E region
45% of viral genome
encodes the proteins that are produced initially
E1,2,4,5,6,7 open reading frames
HPV genome structure - L region
40% of viral genome
encodes the proteins that are produced after synthesis of the proteins of the E region
L1,2 open reading frames
HPV genome structure - non-coding/designated long control (LCR) / upstream regulatory (URR) region
15% of viral genome
involved in the control of viral gene expression
HPV genome structure - role of E proteins
destructs/inactivates TS protein
viral DNA replication
assembly and release of the viral particle
interaction with the epidermal GF
HPV genome structure - role of the L proteins
capsid protein in the viral particle
3 roles of the GDP in oral cancer
primary prevention
secondary prevention
overall health care of OSCC pt
primary prevention
educate pts about oral cancer and its risk factors
secondary prevention
early detection of OPMDs and OSCC - oral cancer screening
referral if suspicious
GDP role in overall healthcare of OSCC pt
1 - pre-tx phase: be involved, be present at tumour board, make accurate and appropriate recommendations
2 - post-tx phase: help in alleviating pain and discomfort due to tx
3 - long-term followup: advise pt in maintaining good OH and attending regular dental visits
high risk HPV
16 and 18
how long does high risk HPV infection typically last?
12-18 months before eventually being cleared by immune system
when can dysplasia from HPV16 or 18 arise?
when the host immune system fails to clear and it persists for a long time
describe the oncogenic HPV function pathway if the immune system fails to clear it
viral E2 protein (a negative regulator of E6+7) function gets abrogated
over expression of main viral oncoprotein E6+7
subsequent inhibition of the TSPs p53 and pRb (retinoblastoma protein) pathways
leads to inhibition of interferon response, activation of telomerase, promotion of cell divisions, immortalisation and transformation
causes genetic instability with unregulated cell replication and accumulation of aberrant chromosomal mutations, which cause dysplasia of varying degrees
why can’t early diagnosis of HPV-related OSCC be accurately established?
because clinical lesions of early HPV-related lesions are unknown
what does HPV+ OSCC have a significant association with?
history of suspicious Pap results of the cervix in females
what risk do unvaccinated pts for HPV have of developing OPC?
x19 risk
why is there a genetic susceptibility to cancer?
because carcinogenesis is a multistep process at both the phenotypic and genetic levels, resulting from the accumulation of multiple mutations
acquired (env) DNA damaging agents
chemicals
radiation
viruses
2 types of inherited mutations
genes affecting DNA repair
genes affecting cell growth or apoptosis
why do you get mutations in genome of somatic cells?
failure of DNA repair and inherited mutations
3 effects of mutations in genome of somatic cells
activation of growth-promoting oncogenes
inactivation of TSGs
alterations in genes that regulate apoptosis
leads to
unregulated cell proliferation and decreased apoptosis
which leads to clonal expansion
from clonal expansion what contributes to tumour progression?
angiogenesis
escape from immunity
additional mutations
what 3 factors combine to to ensure a proper env for malignant development?
genetic events
risk factors
epigenetic mechanisms
what are epigenetic events?
“heritable phenotype changes that do not involve alterations in the DNA sequence”
give 3 examples of epigenetic events
DNA methylation
histone modifications
miRNAs