Carboplatin versus cetuximab chemoradiation in cisplatin ineligible locally advanced head and neck squamous cell carcinoma.

Abstract

e18555 Background: Squamous cell carcinomas (SCC) of Head and neck are associated with tobacco, alcohol use and HPV infection. About 60% of patients with head and neck cancers(HNC) are locally advanced on diagnosis. Concurrent chemoradiation (CCRT) is standard of care in inoperable locally advanced HNC(LA-HNC), high risk adjuvant setting and organ function preservation. While cisplatin (CDDP) is the standard of care for CCRT, alternatives are carboplatin alone or cetuximab alone or carboplatin in combination with 5-FU or paclitaxel CCRT in CDDP ineligible setting. Methods: Patients with LA-HNC (SCC), from 01/01/2013-12/31/2018, who were ineligibile for CDDP CCRT and who received either carboplatin or cetuximab CCRT were included. Patients who received induction chemotherapy and had nasopharynx primary were excluded. 68 patients were analyzed to evaluate outcomes in patients who received carboplatin CCRT and cetuximab CCRT. Progression free survival (PFS) and Overall survival (OS) were calculated by Kaplan Meier analysis with SPSS v26. Results: There was a trend toward improved PFS in CarboRT group among oropharynx HNC patients who were P16 Negative(-ve) (59.5 months(m) vs 37.7 m, p value – 0.069). Among oropharynx HNC patients who were p16 positive, there was no statistically significant difference in PFS among CarboRT vs CetuximabRT (45.8 m vs. 39.77 m, p value – 0.51). OS was favorable towards carboRT in oropharynx SCC p16-ve group (59.5 m vs. 40.97 m, p value – 0.41). There was no difference in OS in p16+ve Oropharynx SCC group, who received CarboRT and CetuximabRT (45.74 vs. 45.94 m, p value – 0.77). When patients were analyzed regardless of their p16 status, site or stage, patients who received CarboRT had a higher OS at 56.30 m (95% CI 45.10-67.50%) vs. 38.11 m (95% CI 28.84-47.38%) among patients who received CetuximabRT (p value-0.048). Though PFS clinically favored carboRT group, when compared to CetuximabRT (55.43 m vs. 36.75 m), it was not statistically significant (p value – 0.10). Conclusions: In our analysis, patients who received single agent carboplatin CCRT had higher OS when compared to cetuximab CCRT. Though other outcomes favored carboplatinRT including PFS among entire group and p16-ve group, OS in p16-ve patients, it was not statistically significant, which is likely due to low power. Based on our analysis, for LA-HNC, carboplatin CCRT should be favored over cetuximab CCRT for patients ineligible for CDDP, particularly in P-16 -ve disease. Further randomized clinical trials can shed more data in this reduced intensity regimen.