Treatment/Prognosis Flashcards
What is the typical Tx paradigm for pts with NPC?
RT alone for stage I, CRT for stages II–IVA, chemo (with RT reserved for focal palliation) for stage IVB
What must be done before planning the NPC pt for RT?
Nutrition consult, dental evaluation are recommended before RT.
When is Sg indicated in the management of NPC?
To Bx the lesion and in cases of selective neck dissection for persistent Dz after CRT.
For early-stage NPC, what are the typical survival and control rates with RT alone?
With RT alone, the 3-yr OS is 70%–100% for stage I–II NPC and LC rates are 70%–80% for T1–T2 lesions.
What stages of NPC should be treated with concurrent chemoradiotherapy (CRT)?
Per the Intergroup 0099 study (Al Sarraf M et al., JCO 1998), all T3–T4 or N+ pts should be considered for CRT. Per RTOG 0225 (Lee N et al., JCO 2009), pts with T2 and N+ Dz should be considered (AJCC 8th edition staging).
What was the CRT regimen used for locally advanced NPC in the Intergroup 0099 (Al-Sarraf et al.) study?
Concurrent chemo with cisplatin (100 mg/m2) q3 wks and RT to 70 Gy → adj chemo with cisplatin/5-FU × 3 cycles
What were the PFS and OS outcomes in the Intergroup 0099 (Al-Sarraf et al.) trial?
In Intergroup 0099, 3-yr PFS was 24% vs. 69%, and 3-yr OS was 46% vs. 76% in favor of CRT over RT alone. B/c of this striking difference, the study was closed early. This was 1 of the 1st studies to demonstrate a survival benefit with CRT.
What are the main criticisms of the Intergroup 0099 (Al-Sarraf et al.) study?
Major criticisms of Intergroup 0099 include the large number of pts (25%) with WHO type I NPC (not typically seen in endemic areas) and the poor results of the RT-alone arm. Single-institution studies with RT alone (PMH: Chow E et al., Radiother Oncol 2002) for locally advanced NPC had better 5-yr DFS (48%) and OS (62%). Other groups (NYU: Cooper JS et al., IJROBP 2000) also demonstrated better outcomes with RT alone (3-yr DFS was 43%, and 3-yr OS was 61%).
What are the 3 key confirmatory randomized trials from Asia that demonstrated a benefit with CRT vs. RT alone for locoregionally advanced NPC?
Hong Kong (NPC-9901: Lee AWM et al., Cancer 2017): 348 pts, RCT, median f/u 10.7 yrs; concurrent cisplatin + RT + adj chemo vs. RT alone, no adj chemo; CRT improved PFS (56% vs. 42%), LRC (87% vs. 74%), and OS (62% vs. 49%, p = .047) but not DM rate; toxicities similar @10 yrs (52% vs. 47%)
Singapore (SQNP01: Wee J et al., JCO 2005): 221 pts, RCT, median f/u 3.2 yrs; used Al-Sarraf regimen: better DFS (72% vs. 53%), OS (80% vs. 65%), and DM rate (13% vs. 30%); greater toxicity with CRT; confirmed results of Intergroup 0099 for endemic NPC
Taiwan (Lin JC et al., JCO 2003): 284 pts, median f/u 5.4 yrs; cisplatin/5-FU + RT vs. RT alone: better PFS (72% vs. 53%) and OS (72% vs. 54%). The subgroup reanalysis (Lin JC et al., IJROBP 2004) showed that CRT benefited low-risk “advanced” NPC (LN <6 cm, no SCV) but not high-risk “advanced” pts
Is there a benefit to the addition of induction chemo followed CRT in locally advanced NPC?
Yes. Sun Trial (Sun et al., Lancet Oncol 2016). 480 pts. RCT of induction TPF f/b CRT vs. CRT alone. Median follow-up 3.75 yrs. Improved 3-yr: FFS (80% vs. 72%), OS (92% vs. 86%), DMFS (90% vs. 83%). No significant difference in LRF.
Is there a benefit with the use of adj chemo after definitive CRT in locally advanced NPC?
Maybe. Network Meta-analysis (Ribassin-Majed et al., JCO 2017) found the addition of adj chemo ranked sup to CRT alone for PFS, LRC and OS. However, only PFS was statistically significant.
Estimate the LC of NPC treated with IMRT to 70 Gy in standard fx.
UCSF data (Lee N, IJROBP 2004) suggests LC rates as high as 97% for NPC pts treated with IMRT.
What is the typical IMRT dose painting technique, and what are the corresponding IMRT doses used in the Tx of NPC?
Many institutions (MSKCC/RTOG) employ the SIB technique: 2.12 Gy × 33 = 69.96 Gy to GTV, 1.8 Gy × 33 = 59.4 Gy to intermediate-risk areas, and 1.64 Gy × 33 = 54 Gy to low-risk areas.
How would you support the use of IMRT in NPC?
Better salivary outcomes with IMRT were demonstrated in data from Queen Mary Hospital (Pow EH et al., IJROBP 2006): 51 pts, stage II NPC, 2D vs. IMRT. At 2 mos, there was no difference in xerostomia; however, over time, QOL and objective salivary function improved for the IMRT group.
