Top Line: Intriguing phase 2 data suggests omitting radiation to a pN0 dissected hemineck after resection of mucosal squamous cell carcinoma might maintain excellent local control.
The Study:This early-phase trial aimed to bring the concept to pre-op radiation for HPV+ oropharyngeal cancer. It enrolled 19 patients, 17 with N1 disease and 2 with N0 disease. Everyone received neoadjuvant durvalumab ± tremelimumab concurrent with stereotactic radiation consisting of 25 Gy in 5 fractions to gross disease only. This means the target was primary tumor and nodal gross disease with a 3 mm planning target volume (PTV). A second cycle of durvalumab ± tremelimumab was given roughly 3 weeks later and transoral robotic surgery (TORS) with ipsilateral neck dissection 2-4 weeks after that all followed by further adjuvant durvalumab for up to 4 cycles. The thought with this combo, here again, was that limiting radiation fields may be particularly synergistic when employing immunotherapy. The good news was that 18 of 19 patients were downstaged on final path and half achieved a complete pathologic response. The bad news was that over a quarter of enrollees (n=5) experienced a locoregional failure, almost exclusively outside the radiation field (n=4). In addition, we’ve also recently learned durvalumab was inferior to cetuximab in patients receiving definitive radiation for HNSCC.
TBL: “Omitting elective volume radiation altogether in an unselected group of patients may be a step too far, resulting in unacceptably high recurrence rate despite the use of neoadjuvant SBRT in combination with immunotherapy followed by resection and elective nodal dissection.” | Ma, Int J Radiat Oncol Biol Phys 2023
The Study:This early-phase trial aimed to bring the concept to pre-op radiation for HPV+ oropharyngeal cancer. It enrolled 19 patients, 17 with N1 disease and 2 with N0 disease. Everyone received neoadjuvant durvalumab ± tremelimumab concurrent with stereotactic radiation consisting of 25 Gy in 5 fractions to gross disease only. This means the target was primary tumor and nodal gross disease with a 3 mm planning target volume (PTV). A second cycle of durvalumab ± tremelimumab was given roughly 3 weeks later and transoral robotic surgery (TORS) with ipsilateral neck dissection 2-4 weeks after that all followed by further adjuvant durvalumab for up to 4 cycles. The thought with this combo, here again, was that limiting radiation fields may be particularly synergistic when employing immunotherapy. The good news was that 18 of 19 patients were downstaged on final path and half achieved a complete pathologic response. The bad news was that over a quarter of enrollees (n=5) experienced a locoregional failure, almost exclusively outside the radiation field (n=4). In addition, we’ve also recently learned durvalumab was inferior to cetuximab in patients receiving definitive radiation for HNSCC.
TBL: “Omitting elective volume radiation altogether in an unselected group of patients may be a step too far, resulting in unacceptably high recurrence rate despite the use of neoadjuvant SBRT in combination with immunotherapy followed by resection and elective nodal dissection.” | Ma, Int J Radiat Oncol Biol Phys 2023