Lung Cancer and Lymphoma Flashcards
1
Q
Classification Lung Cancer
A
- Squamous cell carcinoma
- Small cell carcinoma
- Adenocarcinoma
- Large cell carcinoma
- Mixed
*For treatment, lung cancers are generally groups as non-small cell lung cancer or small cell lung cancer. However, in non-small cells there are still differences in the disease pattern related to the histological subtypes (ex. squamous tend to arise in proximal segmental bronchi, grow slowly, and disseminate late in disease course Vs. adenocarcinoma are often peripheral in origin and have greater risk of metastases ).
*Risk of metastases is greater in small cell (>90% present with metastases).
2
Q
Risk factors for lung cancer
A
- Smoking
- Accounts for ~90% of all lung cancer (Adenocarcinoma has replaced squamous cell as the most common type caused by smoking).
- Radiation therapy - Can increase risk of a second primary lung cancer in patients who have been treated for other cancers (ex. Hodgkins and breat cancer).
- Environmental toxins - exposure to second hand smoke, asbestos, radon, metals, ionizing radiation, and polycylin aromatic hydrocarbon).
- Pulmonary fibrosis
- HIV infection
- Genetic factors
- Alcohol
- Dietary factors
3
Q
Clinical Presentation Lung Cancer
A
- Most patients have advance disease at clinical presentation
- Symptoms may occur due to effects of the tumour (regional or metastatic).
- Cough
- Hemoptysis
- Chest pain (typically on same side of the chest as the tumour).
- Dyspnea
4
Q
Extrathoracic metastases lung cancer
A
- Liver
- Bone
- Adrenal
- Brain
5
Q
Treatment Lung Cancer
A
- Non-small cell lung cancer:
- Surgical resection offers the best opportunity for cure. The appropriateness for surgery depends of preoperative staging and assessment of current pulmonary function to allow predicition of postoperative function.
- Stage I or II - surgical resection if possible + adjuvant chemotherapy for stage II
- Stage III - chemoradiotherapy
- Stage IV - systemic therapy or symptom-based palliative approach
- Small cell lung cancer
- Small cell lung cancer is a disseminated disease in most patients at presentation and is very responsive to chemotherapy
- Limited stage - mainly treated with a combination of chemotherapy and radiation therapy. Prophylatic cranial irradiation decreased incidence of brain metastases and prolongs survival
- Extensive stage - chemotherapy alone is used. Radiation therapy may be beneficial in those who respond to chemotherapy.
6
Q
Staging non-small cell lung cancer
A
- Stage 0 - carcinoma in situ
- Stage 1 - tumour is within the lung and is ≤ 4cm
- Stage 2 -tumour is ≤ 5cm (may have spread to lymph nodes near bronchi)
- Stage 3 -tumour has spread to more distant lymph nodes
- Stage 4 - metastasis
7
Q
Staging small cell lung cancer
A
- Limited stage - small cells lung cancer is only found on one side of the chest. Includes spread to lymph nodes on same side of the tumour or in the mediastinum.
- Extensive stage - cancer has sprea widely to the other lung, the lymph nodes on the side side, or to other parts of the body.
8
Q
Smoking as a carcinogen
A
- Both cigarette smoke and smokeless tobacco contain various carcinogenic chemicals.
- Exposure to carcinogens found in tobacco results in the formation of covalent bonds between carcinogens and DNA ultimately resulting in the formation of DNA adducts (segment of DNA bound to a cancer causing chemical). Adducts result in miscoding and thus permanent mutations in critical genes of somatic cells.
9
Q
Radiation as a carcinogen
A
- Ionizing radiation damages DNA by interacting with molecular cellular components like water, iron, and oxygen to generate free radicals. Free radicales than react with DNA resulting in double - and single- strand breaks, base loss, and base mutations.
- Initiating factor in carcinogenesis is thought to be an induced mutation in a tumour suppressor or proto-oncogene, with a loss or gain of function mutation, respectively.
10
Q
Effects of Radiation
A
- Loss of mature functional cells of apoptosis
- Loss of reproductive capacity - when cells loss is mainly through loss of proliferative capacity, the rate of cell renewal of a certain organ determines the time of appearance of tissue damage from days to years after radiation (acute vs. late effects)
- Acute - changes developing during course of radiotherapy of 6-8 weeks. Involves mainly the mucosa and hemopoietic system - Tissues with fast normal cellular turnover (epithelia of skin and gut, bone marrow) display effects earliest.
- Late - occur mainly in slowly proliferating tissues (lung, kidney, heart, liver, and CNS), but can occur in other tissues as well.
11
Q
Secondary Malignancies
A
- Cancers caused by treatment with radiation or chemotherapy.
- May occur months or years after treatment.
- Occurs as a result of radiation and chemotherapy being carcinogenic themselves.
- Temporal relationship between radiation exposure and development of secondary cancer - 5-10 years for development of leukemia and 10-60 years for a soild tumour.
12
Q
Hodgkins Lymphoma (HL)
A
- A malignant lymphoma characterized by the presence of clonal malignant Hodgkin/Reed-Sternberg (HRS) cells seen in an appropriate cellular background of small lymphoctyes, eosinophils, neutrophils, histiocytes, and plasma cells.
- HL accounts for 7% of childhood cancer - however can occur at all ages with incidence peaks in young adults with small peak seen after 60.
13
Q
Hodgkins Lymphoma Pathogenesis
A
- The cause of HL is unknown, but Epstein-Barr virus has been implicated and is detected in ~40% of cases
- Malignant HRS cells - B cell with nonproductively rearranged immunoglobin heavy chains, down-regulated B cell specific transcription factors, and down-regulated signaling pathways
- HRS Cells -germinal center B cells that cannot synthesize immunoglobulin molecules
14
Q
Hodgkins Lymphoma Presentation
A
- Painless lymphadenopathy (cervical nodes especially)
- Mediastinal mass on CXR
- Systemic symptoms (“B” symptoms)
- Fever
- Night sweats
- Weight loss >10%
- Fatigue
- Anorexia
- Hepatic or splenic enlargement
15
Q
Diagnosis Hodgkins Lymphoma
A
- Goal is to evaluate the extent of disease (determines clinical and pathologic stage, treatment, and prognosis).
- History - complete history with emphasis on constituational symptoms
- Physical exam - general health, height, weight, documentation of size and location of lymphadenopathy, liver and spleen size, skin infiltration, pulmonary findings, and neurologic signs.
- Imaging - goal is to define extent of disease and guide tissue biopsy (CXR; CT of neck, chest, abdoment, and pelvis; PET scan)
- Tissue biopsy
- Laboratory evulation to detemine other organ involvemetn - CBC, liver function tests, lactate, urinalysis, etc.
