[Radiotherapy and curietherapy of squamous cell carcinoma of the posterior pharyngeal wall (excluding the nasopharynx)].

From 1986 to 1992, 55 cases of PPWC were treated with a conservative intent at the Regional Cancer Center (Rennes, France) and Saint-Yves Center (Vannes, France): 16 oropharyngeal posterior wall carcinoma (OP) and 39 hypopharyngeal posterior wall (HP); the mean age of the population was 60.3 years (31-81 years). A previous and simultaneous head and neck cancer was noted in 15 and 13% of cases respectively. Half of the cases (55%) were T1 T2 tumors and 82% were N0 N1. Except for three patients treated by curietherapy (5%), all patients were treated by radiotherapy (RT) alone (75%) or associated with curietherapy (7%) or partial pharyngectomy (13%). 15% received neoadjuvant chemotherapy, mainly for T3 tumors. With a followup of 4-88 months (mean: 23 months) 38% of patients are still alive; 8% of loco-regionally controlled patients died of second cancer or intercurrent disease. The tumor control was 67%. The nodes control was 90%. During the course of the disease, 19% of patients had metastases. The complete response at the end of treatment was 78%. Among these patients, 54% remained definitively free of disease. There is no difference between OP and HP. The analysis of survival curves showed the following points: significant difference between T1 T2, and T2 T3 (P < 0.05), N0 N1 and N2 N3 (P < 0.03), well differentiated histology or not (P < 0.02), RT alone or associated with curietherapy or surgery (P < 0.03) even for limited tumors T1 T2 N0 N1 (P < 0.03). There was no significant difference between group treated or not by chemotherapy even for T3 tumors. These findings do not differ if we consider either OP or HP. We conclude that OP and HP have the same prognostic factors and must be considered as the same clinical entity. For limited tumors T1 T2 N0 N1, patients managed by radiotherapy associated with complementary local treatment (conservative surgery or curietherapy) do better than patients treated by RT alone (plateau 80% at 18 months+vs plateau 25% at 12 months +). For these limited tumors, our recommendation is to treat patients by external RT (50 Gy) and curietherapy boost (20 Gy) rather than by conservative surgery and external RT (70 Gy). These two treatments have the same efficacity but the first one is expected to diminish late complications of RT. Neo adjuvant chemotherapy does not seen to improve survival even for advanced tumors. Generally speaking these results remain poor for locally advanced desease and for undifferentiated tumors. These patients need a new therapeutic approach (concomittant radio-chemotherapy, hyper or hypofonctionnated RT).