Goodman, Karyn A.

1 Background: To determine whether changing chemotherapy (CT) during pre-op chemoradiation (CRT) based on response to induction CT by 18F-fluoro-deoxyglucose PET imaging can lead to improved pathologic complete response (pCR) in patients (pts) with resectable esophageal and gastroesophageal junction (GEJ) adenocarcinomas. Methods: 257 eligible pts were enrolled, underwent baseline PET scan, and were randomized to one of 2 induction CT arms: Modified FOLFOX-6 (oxaliplatin, leucovorin, 5-FU), days 1, 15, 29 or Carboplatin/Paclitaxel (CP), days 1, 8, 22, 29. Repeat PET was performed days 36-42; change in max standardized uptake value (SUV) from baseline was assessed. PET non-responders (≤35% decrease in SUV – PET-NR) crossed over to alternative CT regimen during CRT (50.4Gy/28 fractions). PET responders (>35% decrease in SUV – PET-R) continued on same CT during CRT. Pts underwent surgery 6 wks post-CRT. Pts evaluable if had surgery, disease progression (PD), death due to disease, were unresectable or had adverse event (AE). Primary endpoint was pCR in PET-NR who crossed over to alternative CT (expected 5% under H0 to 20% under Ha). Results: Pre-audit PET response data after induction CT and pCR rates after CRT and surgery are shown in the table. For PET-NR who crossed over to alternative CT during CRT, pCR was 15.6%; 95% CI (0.08, 0.26). Conclusions: Efficacy criteria were met for an improvement in pCR rates among pts who were PET-NR after induction CT and received alternative CT during CRT for esophageal and GEJ adenoca. Pts receiving induction and concurrent CP had an unexpectedly low pCR. Support: U10CA180821, U10CA180882 Clinical trial information: NCT01333033. [Table: see text]

523 Background: This study was done to assess the toxicity and efficacy of IMRT for anal cancer in a multi-institutional setting. Methods: Records of 152 total patients (pts) were reviewed retrospectively. Data on disease control and toxicity were collected as well as pt and treatment characteristics. Acute (<6 months) and late (>=6 months) severe toxicity (grade >=3) were recorded at each institution. Four were excluded for either presence of metastatic disease (2) or stage TX (2). There was data for late toxicity on 120 pts. Results: T stage was T1 in 28, T2 in 79, T3 in 29 and T4 in 12 pts. N stage was N0 in 77, N1 in 40, N2 in 19 and N3 in 12 pts. The median age was 56 yrs and median follow-up was 26.8 months. Cumulative IMRT dose was 51.25 Gy (median) (range: 4.32-61.2 Gy) in a median of 28 fractions (2-34). Chemotherapy was given in all but 2 pts and the most common regimen was 5- fluorouracil plus mitomycin-C. The median total elapsed treatment time was 40 days. Local control at 3 yrs was 87% and was significantly worse for patients with T3-4 disease (79% vs 90% at 3 years; p=0.04). There was no correlation between dose and local control. Regional control, distant control and overall survival were 97%, 91%, and 87% at 3 yrs, respectively. Nodal status was associated with regional and distal control as well as overall survival (p<0.01 for each). The most common acute severe toxicity was hematologic (41%). Severe acute GI, skin or other toxicity was 11%, 20% and 1% respectively. There were two grade 5 toxicities (hematologic and GI). Severe late toxicity was limited to skin (1%) and GI (3%). Conclusions: IMRT resulted in excellent local control in this multi-institutional cohort of pts. Although T stage did predict for worse local control, most pts with T3-4 disease were controlled with IMRT. Nodal status predicts for regional and distal control as well as overall survival. Severe toxicity was acceptable with this technique.