Forastiere, Arlene A.

6026 Background: We examined a large patient dataset based on E1305, a completed phase III randomized trial of platinum-based chemotherapy with or without bevacizumab (Argiris et al. JCO 2019), to evaluate prognostic factors in the first-line treatment of patients with recurrent or metastatic squamous cell carcinoma of the head and neck (RM SCCHN) and expand on our previous observations in cooperative group trials (Argiris et al. Cancer 2004). Methods: All 403 patients enrolled in E1305 were analyzed. Overall survival (OS) was the outcome of interest. Clinical and tumor characteristics were examined using Cox proportional hazards models. Variables which were significant in the univariate setting at a level of ≤ 0.10 were included in a multivariable model, and backwards selection was performed (threshold of p ≤ 0.05). The final multivariable model was then applied to the two treatment arms, separately. Variables for which the hazards ratio (HR) within an arm was more than 10% different than that for the whole cohort, were removed from the final cohort model. Results: The median OS in the whole study cohort was 11.8 months. A prognostic score model for OS was built, using the 4 independent prognostic factors identified in the multivariable model: ECOG performance status (1 vs 0), prior radiation, primary region (non-oropharynx vs oropharynx), and metastatic disease bone or liver (vs other sites/no metastases). Prognostic score was dichotomized (0-2 and > 2). Patients with 0-2 risk factors (n = 249) had a median OS of 15.2 months (90% CI: 13.8, 18.1), while patients with > 2 risk factors (n = 154) had a median OS of 7.6 months (90% CI: 6.5, 9.3); HR of 2.14 (95% CI: 1.73, 2.66), p < 0.0001. Compared to our previous 5-factor model from analysis of older trials in a similar setting, the variable “bone/liver metastasis” is new, but “tumor cell differentiation” and “weight loss” were not significant and not included in the new model for OS. Conclusions: The new proposed model includes 4 prognostic factors for OS (performance status, primary site, prior radiation, presence of bone/liver metastasis) in the first-line treatment of RM SCCHN.

4530 Background: EAC has eluded cure even with platin-based CRT. Stratifying pts by likelihood of success is one approach to improving outcomes. We assessed whether SNPs in DNA repair paths are associated with complete pathologic response (pCR) in EAC pts who received C-based CRT followed by surgery. Methods: Patients and specimens: Pretreatment biopsy or post-CRT resection samples were obtained from pts (EAC, stage II-IVa) treated on a randomized phase II trial, E1201 (n=86), of preop CRT (RT to 45 Gy). Arm A: Preop C 30 mg/m2 + irinotecan (I) 50 mg/m2 days (d) 1, 8, 22, 29 with RT. Post-op C 30 mg/m2 + I 65 mg/m2 d 1, 8 q21 days x 3. Arm B: Preop C 30 mg/m2 + paclitaxel (P) 50 mg/m2 d 1, 8, 15, 22, 29 with RT. Post-op C 75 mg/m2 + P 175 mg/m2 d 1 q21 days x 3. Clinical outcome - pCR: (A) 14% [95% CI 5.5%, 28.5%]; (B) 16% [95% CI 6.7%, 30.1%]. Median overall survival (OS): (A) 34.9 m (months) [90% CI 23.5, not reached]; (B) 20.9 m [90% CI 17.4, 46.7]. Experimental procedure: Normal tissue was microdissected from unstained sections of paraffin-embedded tissue. DNA was extracted (Qiagen). Genotyping was performed by matrix-assisted laser desorption/ionization time-of-flight (Sequenom) for all SNPs. Each SNP was dichotomized a priori into: (1) major homozygote vs (2) minor (heterozygote plus minor homozygote) allele groups. Data analysis was performed centrally, with lab investigators blinded to clinical data. Exact logistic regression was used to derive ORs for non-pCR, using the major homozygote as the reference (2-sided p values). Results: Germline DNA was available in 68 pts; 60 were eligible and began therapy ( Table ). Conclusions: In this homogenous, well-defined cohort, the XRCC1 Arg399Gln minor allele group was associated with lower pCR (p=0.06). Lab data on a panel of additional SNPs have been collected and are under analysis for presentation at the meeting. [Table: see text] [Table: see text]

6016 Background: A germline mutation in let-7 complementary site 6 (LCS6) within the KRAS 3'-untranslated region (rs61764370, the KRAS-variant: TG/GG) is known to associate with poor outcome and drug resistance in various cancers compared to the wild type allele (TT). We examine the prognostic significance of the KRAS-variant in recurrent/metastatic (R/M) head and neck squamous cell carcinoma (HNSCC). Methods: The KRAS-variant was determined in 116 tumor DNA samples from HNSCC patients enrolled in 3 clinical trials and a tissue collection study using a previously validated PCR-based assay. Results: KRAS-variant status could be determined in 108/116 (93%) samples and an allele frequency of TG/GG was 28.7%. These results were correlated with patient demographics, p16/human papillomavirus (HPV) status and clinical outcome. There was no association between p16/HPV status and the KRAS-variant status (Fisher’s exact test, p=1.0). The KRAS-variant was associated with poor progression-free survival in patients treated with cisplatin+/-cetuximab (log-rank p=0.002) but this association was not observed in docetaxel/bortezomib treated patients (log-rank p=0.89). Conclusions: KRAS-variant is a potentially promising biomarker of poor prognosis and a predictive biomarker of cisplatin resistance in R/M HNSCC. Prospective validation is warranted. Clinical trial information: NCT00003809.

6028 Background: Abnormalities in EGFR signaling targets are associated with C resistance but no biomarker of C resistance has been identified in HNSCC. We hypothesized that cases with loss of PTEN protein expression (PTEN null) or PIK3CA mutation would display C resistance in HNSCC. Methods: E5397 was a phase III trial of CDDP plus P or CDDP plus C and enrolled 117 eligible and evaluable pts. PIK3CA and PTEN were analyzed for 52 and 67 consented pts, respectively. PTEN expression (PTEN Cell Signaling Technology, Cat. 9559) was determined by automated quantitative analysis (AQUA) on the PM-2000 (HistoRx, New Haven) using a cutpoint generated in 5 HNSCC tissue microarrays, each consisting of HNSCC as well as positive (small intestine, median AQUA score 2833.2) and negative controls (breast and colon carcinoma, median AQUA score 205.5). A cutpoint of 570 provides 100% specificity, 100% sensitivity, and identified 30% of the HNSCCs as PTEN null, consonant with the literature. The 3 most common PIK3CA mutations (E542K and E545K in exon 9 and H1047R in exon 20) were determined by BEAMing (Inostics, Heidelberg, Germany). Response, overall survival (OS) and progression-free survival (PFS) were compared between PTEN null or PIK3CA mutated pts and all others. Log rank and multivariable Cox proportional hazards modeling were used to calculate p values. Results: 23/67 (34%) tumors were PTEN null and 2/52 (4%) had PIK3CA mutations (E542K and E545K). Both tumors with PIK3CA mutation had PTEN expression. No statistically significant differences in response, OS or PFS were noted in this small sample. However, among PTEN expressing/PIK3CA WT pts, median PFS increased to 4.2 months (m) for C (N=22) from 2.9 m for P (N=26) (Wald p=0.07), compared with 4.6 m for C (N=12) and 3.5 m for P (n=13) among the PTEN null/PIK3CA mutated (Wald p=0.60). Conclusions: The PTEN loss or PIK3CA mutation signature warrants further investigation as a predictor of C resistance.

Abstract Lesson Learned Panitumumab plus irinotecan is not active for the treatment of esophageal adenocarcinoma. Background Esophageal adenocarcinoma (EAC) is a lethal cancer with increasing incidence. Panitumumab (Pa) is a fully humanized IgG2 monoclonal antibody against human EGFR. Cetuximab (Cx) combined with irinotecan (Ir) is active for second-line treatment of colorectal cancer. This phase II study was designed to evaluate Pa plus Ir as second-line therapy for advanced EAC. Methods The primary endpoint was response rate (RR). Patients with one prior treatment were given Pa 9 mg/m2 on day 1 and Ir 125 mg/m2 on days 1 and 8 of each 21-day cycle. Inclusion criteria were confirmed EAC, measurable disease, no prior Ir or Pa, performance status &lt;2, and normal organ function. Results Twenty-four patients were enrolled; 18 were eligible and evaluable. These patients were all white, with a median age of 62.5 years (range, 33–79 years), and included 15 men and 3 women. The median number of cycles was 3.5. The most common grade 1–2 adverse events were fatigue, diarrhea, anemia, leukopenia, and hypoalbuminemia. Grade 3–4 adverse events included hematologic, gastrointestinal, electrolyte, rash, fatigue, and weight loss. The median follow-up was 7.2 months (range, 2.3–14 months). There were no complete remissions. The partial response rate was 6% (1/18; 95% confidence interval [CI], 0.01–0.26). The clinical benefit (partial response [PR] plus stable disease [SD]) rate was 50%. The median overall survival was 7.2 months (95% CI, 4.1–8.9) with an 11.1% 1-year survival rate. The median progression-free survival was 2.9 months (95% CI, 1.6–5.3). Conclusion Irinotecan and panitumumab as second-line treatment for advanced EAC are not active.

Abstract Background: Esophageal adenocarcinoma (EAC) is a lethal cancer, and the incidence is increasing. Our group demonstrated that over-expression of the epidermal growth factor receptor (EGFR) correlated with reduced survival in EAC. Panitumumab (P) is a fully human IgG2 monoclonal antibody against human EGFR. Cetuximab combined with irinotecan (I) has shown activity for second-line treatment of advanced colorectal cancer (CRC). P alone is active in EGFR expressing CRC as well. Our group has empiric evidence for the activity of cetuximab + I as third-line treatment for advanced EAC. As such, a phase II study was designed to evaluate P + I as second-line therapy for advanced EAC. Trial Design: The primary endpoint is overall response (OR) as measured by RECIST (cross-sectional imaging every 2 cycles). Secondary endpoints include overall survival, safety/toxicity and correlative studies. Patients with confirmed EAC with history of one prior treatment are treated with P 9 mg/m2 on day 1 and I 125 mg/m2 on days 1 and 8 of each 21 day cycle to a maximum of 6 cycles. Inclusion criteria include confirmed EAC, measurable disease, no prior I or P, PS &lt;2 and normal organ function. A Simon two-stage design is used with power of 80% and a type I error of 0.05. 18 patients will be tested in the first stage and will terminate the trial if 2 or fewer respond. A total of 43 patients will be studied. Blood and tissue are obtained to analyse the role of FCα-R receptors as well EGFR pathway components and kras mutations. Enrollment: The 1st patient was enrolled in May 2009. Through August 2011, 7 patients received treatment. Preliminary results: Of the 7 patients treated, all are white males, median age 62. 2 patients completed 6 cycles. 1 patient received 3 cycles, 3 received 2 cycles and 1 patient completed 1 cycle. 3 patients are still alive. However, only 1 patient is still in the trial. 4 patients received dose reductions due to grade 3 or 4 side effects, including GI disturbances (5), fatigue(1), skin rash(1), electrolyte imbalances(2) and hematologic abnormalities (5). Reasons for discontinuation included progressive disease (PD, 5 patients) and patient refusal (2). The longest survival was 338 days–1 of the 2 patients who completed 6 cycles. The second patient who completed 6 cycles is alive at 307 days. 1 patient completed 3 cycles and survived 213 days after PD. 1 patient survived 174 days followed PD after 2 cycles. 2 patients completed 2 cycles and are still alive, surviving 151 (pt refusal) and 103 days respectively. The shortest survival was 85 days who completed only 1 cycle. Conclusion: Preliminary data from this Phase II trial suggests that patients with advanced EAC might benefit from P+I regimen as 2nd line therapy. 3 additional centers will open the trial. Accrual is ongoing, and correlative studies will follow. This project used the University of Pittsburgh Cancer Institute and was supported in part by award P30CA047904 Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3708. doi:1538-7445.AM2012-3708