Use of restaging primary site biopsy to optimize selection of primary therapy in high stage (III/IV) squamous cancer

Abstract

6042 Background: A consecutive series of neoadjuvant protocols has focused on restaging re-biopsy to select therapy of Stage III/IV squamous cancer since 1995. Patients with positive restaging biopsy have subsequent resection whereas those having a negative re-biopsy have completion chemo- radiation therapy of primary site to total dose 68–72cGy. We are currently reporting the benefit of giving induction chemotherapy prior to chemoradiation. Methods: Initial protocols (H&N 53& 67) utilized concurrent preoperative Paclitaxel (P) (60mg/M² or 40mg/M2) + Carboplatin (AUC) + RT (45G) 67(64 evaluable pts). Subsequent studies (H&N79) utilized induction chemo (P 135mg/M², C (2AUC) weekly x 6 followed by chemoradiation therapy P 40 C (1AUC) + 45 Gy (H&N79) 32 pts (13 operable). Results: Protocols, 53 & 67 induced a complete pathologic response in 70% vs. a 52% clinically determined CR permitting completion radiation with primary site preservation. Neck dissection (ND) revealed persistent disease in 37% confirming need for ND in N1–3 disease. Induction therapy followed by chemo radiation therapy (H + N #79) induced path CR of 86%. Survival OS & DFS were equivalent in patients having Completion Radiation by chemo Radiation or Surgery (OS 44%/54%) (DFS 54%/54%). Factors associated with persistent cancer at the primary site were high T stage (T 3 & 4) present in 94% of patients requiring resection vs. 58% in patients having a path CR. Other risk factors were location-base of tongue, larynx and mandible involvement. Conclusion: Restaging biopsy after neoadjuvant chemo radiation is superior to clinical/radiologic assessment in demonstrating a complete response to therapy and permitted completion radiation therapy and primary site organ preservation in 70%–86% of pts. Early biopsy directed surgical salvage (RO) for persistent primary tumor permits tumor eradication with survival and disease control that is equivalent to the more biologically favorable chemo radiation group. H & N Protocol (Pts) Concurrent Chemo/RT/Induction Rx-C-RT Stage III/IV Clinical Response (primary site) Path (CR%) Residual CA in Neck Survival OS/DFS C-RT (Pts) S (Pts) #53 (38) #67 (26) (64) P+C+ 45Gy 24/40 31 PR 48% 32 CR 52% 45/64 (70%) 17/46 (37%) (45) 44%/54% (18) 55%/54% #79 (30) Induction →Chem RT P + C →P+C+RT 10/20 10 PR (33%) 20 CR (67%) 26/30 (86%) 9/30 (30%) (26) 55%/45% (4) NA/NA No significant financial relationships to disclose.