Subsite-dependent prognostic impact of age in patients with nasopharyngeal and oropharyngeal cancer

Abstract

Backgroud: Outcome results in elderly head and neck cancer (HNC) patients (pts) treated with concurrent chemoradiation are controversial. Comparative effectiveness analyses showed a lack of benefit in multimodal treatment; however, retrospective highly selected series reported older patients to have similar outcome compared to younger ones albeit with high burden of toxicities. Material and methods: Locally advanced oropharyngeal (OPC) and nasopharyngeal cancer (NPC) pts treated at our institution with concurrent platinum based chemotherapy (CHT) and intensity modulated radiation therapy (IMRT) techniques from 2004 to 2015 were retrospectively evaluated. Overall survival (OS) and Relapse Free Survival (RFS) Kaplan-Meier curves were estimated and compared with the log-rank test; acute toxicity rate >G3 according to Common Toxicity Criteria Adverse Event v4.0 was also analyzed, distinguishing between patients >65 years old (elderly) and ≤65 old. HPV status was recorded in all OPC patients. Results: 375 pts received IMRT-CHT, 215 in OPC and 160 in NPC cohort. Elderly pts represented 26% and 11% of OPC and NPC pts, respectively. OPC HPV positive cases were similarly represented in older (73% of the cases) and younger pts (66%); HPV positivity maintained a significant prognostic role independently of age and also across different age group. On the contrary, age did not significantly impact on survival in OPC. Five-years RFS was 68% in older versus 76% in younger patients p = 0.391; the corresponding figures for OS were 93% versus 87% p = 0.541. There was no significant difference in cumulative acute toxicity rate = G3 (39% in elderly vs 36% in younger p = 0.778). When analyzed separately, no difference was shown for what concerns dysphagia and mucositis. NPC pts showed a different outcome according to age both in terms of RFS (5-years probabilities 41% in elderly vs 80% in younger pts, p < 0.001) and OS (48% vs 90%, p < 0.001), which turned out to be a negative prognostic factor in this disease. Also for NPC pts, the two age subgroups did not significantly differ in acute toxicity rate = G3 (56% vs 61%, p = 0.800). No different platinum total dose was adopted in OPC and NPC elderly pts. Conclusion: We observed a subsite-specific impact of age on treatment outcome: older NPC pts showed markedly worse survival than the younger counterparts, while in OPC pts such an effect was inconsistent. HPV status was confirmed to be a positive prognostic factor independently of age.