Neoplasia risk in patients with Lynch syndrome treated with immune checkpoint blockade

Metastatic and localized mismatch repair-deficient (dMMR) tumors are exquisitely sensitive to immune checkpoint blockade (ICB). The ability of ICB to prevent dMMR malignant or pre-malignant neoplasia development in patients with Lynch syndrome (LS) is unknown. Of 172 cancer-affected patients with LS who had received ≥1 ICB cycles, 21 (12%) developed subsequent malignancies after ICB exposure, 91% (29/32) of which were dMMR, with median time to development of 21 months (interquartile range, 6-38). Twenty-four of 61 (39%) ICB-treated patients who subsequently underwent surveillance colonoscopy had premalignant polyps. Within matched pre-ICB and post-ICB follow-up periods, the overall rate of tumor development was unchanged; however, on subgroup analysis, a decreased incidence of post-ICB visceral tumors was observed. These data suggest that ICB treatment of LS-associated tumors does not eliminate risk of new neoplasia development, and LS-specific surveillance strategies should continue. These data have implications for immunopreventative strategies and provide insight into the immunobiology of dMMR tumors.

Zolbetuximab plus CAPOX in CLDN18.2-positive gastric or gastroesophageal junction adenocarcinoma: the randomized, phase 3 GLOW trial

There is an urgent need for first-line treatment options for patients with human epidermal growth factor receptor 2 (HER2)-negative, locally advanced unresectable or metastatic gastric or gastroesophageal junction (mG/GEJ) adenocarcinoma. Claudin-18 isoform 2 (CLDN18.2) is expressed in normal gastric cells and maintained in malignant G/GEJ adenocarcinoma cells. GLOW (closed enrollment), a global, double-blind, phase 3 study, examined zolbetuximab, a monoclonal antibody that targets CLDN18.2, plus capecitabine and oxaliplatin (CAPOX) as first-line treatment for CLDN18.2-positive, HER2-negative, locally advanced unresectable or mG/GEJ adenocarcinoma. Patients (n = 507) were randomized 1:1 (block sizes of two) to zolbetuximab plus CAPOX or placebo plus CAPOX. GLOW met the primary endpoint of progression-free survival (median, 8.21 months versus 6.80 months with zolbetuximab versus placebo; hazard ratio (HR) = 0.687; 95% confidence interval (CI), 0.544-0.866; P = 0.0007) and key secondary endpoint of overall survival (median, 14.39 months versus 12.16 months; HR = 0.771; 95% CI, 0.615-0.965; P = 0.0118). Grade ≥3 treatment-emergent adverse events were similar with zolbetuximab (72.8%) and placebo (69.9%). Zolbetuximab plus CAPOX represents a potential new first-line therapy for patients with CLDN18.2-positive, HER2-negative, locally advanced unresectable or mG/GEJ adenocarcinoma. ClinicalTrials.gov identifier: NCT03653507 .

Zolbetuximab plus mFOLFOX6 in patients with CLDN18.2-positive, HER2-negative, untreated, locally advanced unresectable or metastatic gastric or gastro-oesophageal junction adenocarcinoma (SPOTLIGHT): a multicentre, randomised, double-blind, phase 3 trial

BACKGROUND

Zolbetuximab, a monoclonal antibody targeting claudin-18 isoform 2 (CLDN18.2), has shown efficacy in patients with CLDN18.2-positive, human epidermal growth factor receptor 2 (HER2)-negative, locally advanced unresectable or metastatic gastric or gastro-oesophageal junction adenocarcinoma. We report the results of the SPOTLIGHT trial, which investigated the efficacy and safety of first-line zolbetuximab plus mFOLFOX6 (modified folinic acid [or levofolinate], fluorouracil, and oxaliplatin regimen) versus placebo plus mFOLFOX6 in patients with CLDN18.2-positive, HER2-negative, locally advanced unresectable or metastatic gastric or gastro-oesophageal junction adenocarcinoma.

METHODS

SPOTLIGHT is a global, randomised, placebo-controlled, double-blind, phase 3 trial that enrolled patients from 215 centres in 20 countries. Eligible patients were aged 18 years or older with CLDN18.2-positive (defined as ≥75% of tumour cells showing moderate-to-strong membranous CLDN18 staining), HER2-negative (based on local or central evaluation), previously untreated, locally advanced unresectable or metastatic gastric or gastro-oesophageal junction adenocarcinoma, with radiologically evaluable disease (measurable or non-measurable) according to Response Evaluation Criteria in Solid Tumors version 1.1; an Eastern Cooperative Oncology Group performance status score of 0 or 1; and adequate organ function. Patients were randomly assigned (1:1) via interactive response technology and stratified according to region, number of organs with metastases, and previous gastrectomy. Patients received zolbetuximab (800 mg/m2 loading dose followed by 600 mg/m2 every 3 weeks) plus mFOLFOX6 (every 2 weeks) or placebo plus mFOLFOX6. The primary endpoint was progression-free survival assessed by independent review committee in all randomly assigned patients. Safety was assessed in all treated patients. The study is registered with ClinicalTrials.gov, NCT03504397, and is closed to new participants.

FINDINGS

Between June 21, 2018, and April 1, 2022, 565 patients were randomly assigned to receive either zolbetuximab plus mFOLFOX6 (283 patients; the zolbetuximab group) or placebo plus mFOLFOX6 (282 patients; the placebo group). At least one dose of treatment was administered to 279 (99%) of 283 patients in the zolbetuximab group and 278 (99%) of 282 patients in the placebo group. In the zolbetuximab group, 176 (62%) patients were male and 107 (38%) were female. In the placebo group, 175 (62%) patients were male and 107 (38%) were female. The median follow-up duration for progression-free survival was 12·94 months in the zolbetuximab group versus 12·65 months in the placebo group. Zolbetuximab treatment showed a significant reduction in the risk of disease progression or death compared with placebo (hazard ratio [HR] 0·75, 95% CI 0·60-0·94; p=0·0066). The median progression-free survival was 10·61 months (95% CI 8·90-12·48) in the zolbetuximab group versus 8·67 months (8·21-10·28) in the placebo group. Zolbetuximab treatment also showed a significant reduction in the risk of death versus placebo (HR 0·75, 95% CI 0·60-0·94; p=0·0053). Treatment-emergent grade 3 or worse adverse events occurred in 242 (87%) of 279 patients in the zolbetuximab group versus 216 (78%) of 278 patients in the placebo group. The most common grade 3 or worse adverse events were nausea, vomiting, and decreased appetite. Treatment-related deaths occurred in five (2%) patients in the zolbetuximab group versus four (1%) patients in the placebo group. No new safety signals were identified.

INTERPRETATION

Targeting CLDN18.2 with zolbetuximab significantly prolonged progression-free survival and overall survival when combined with mFOLFOX6 versus placebo plus mFOLFOX6 in patients with CLDN18.2-positive, HER2-negative, locally advanced unresectable or metastatic gastric or gastro-oesophageal junction adenocarcinoma. Zolbetuximab plus mFOLFOX6 might represent a new first-line treatment in these patients.

FUNDING

Astellas Pharma, Inc.

Waiting to Operate: The Risk of Salvage Esophagectomy

OBJECTIVE

To assess postoperative morbidity, disease-free survival (DFS), and overall survival (OS) in patients treated with salvage esophagectomy (SE).

BACKGROUND DATA

A shift toward a "surgery as needed" approach for esophageal cancer has emerged, potentially resulting in delayed esophagectomy.

METHODS

We identified patients with clinical stage I-III esophageal adenocarcinoma or squamous cell carcinoma who underwent chemoradiation followed by esophagectomy from 2001 to 2019. SE was defined as esophagectomy performed >90 days after chemoradiation ("for time") and esophagectomy performed for recurrence after curative-intent chemoradiation ("for recurrence"). The odds of postoperative serious complications were assessed by multivariable logistic regression. The relationship between SE and OS and DFS were quantified using Cox regression models.

RESULTS

Of 1137 patients identified, 173 (15%) underwent SE. Of those, 61 (35%) underwent SE for recurrence, and 112 (65%) underwent SE for time. The odds of experiencing any serious complication [odds ratio, 2.10 (95% CI, 1.37-3.20); P =0.001] or serious pulmonary complication [odds ratio, 2.11 (95% CI, 1.31-3.42); P =0.002] were 2-fold higher for SE patients; SE patients had a 1.5-fold higher hazard of death [hazard ratio, 1.56 (95% CI, 1.25-1.94); P <0.0001] and postoperative recurrence [hazard ratio, 1.43 (95% CI, 1.16-1.77); P =0.001]. Five-year OS for nonsalvage esophagectomy was 45% [(95% CI, 41.6%-48.6%) versus 26.5% (95% CI, 20.2%-34.8%) for SE (log-rank P <0.001)]. Five-year OS for SE for time was 27.1% [(95% CI, 19.5%-37.5%) versus 25.2% (95% CI, 15.3%-41.5%) for SE for recurrence ( P =0.611)].

CONCLUSIONS

SE is associated with a higher risk of serious postoperative complications and shorter DFS and OS.

Prognosis after neoadjuvant chemoradiation or chemotherapy for locally advanced gastro-oesophageal junctional adenocarcinoma

BACKGROUND

Trials typically group cancers of the gastro-oesophageal junction (GOJ) with oesophageal or gastric cancer when studying neoadjuvant chemoradiation and perioperative chemotherapy, so the results may not be fully applicable to GOJ cancer. Because optimal neoadjuvant treatment for GOJ cancer remains controversial, outcomes with neoadjuvant chemoradiation versus chemotherapy for locally advanced GOJ adenocarcinoma were compared retrospectively.

METHODS

Data were collected from all patients who underwent neoadjuvant treatment followed by surgery for adenocarcinoma located at the GOJ at a single high-volume institution between 2002 and 2017. Postoperative major complications and mortality were compared between groups using Fisher's exact test. Overall survival (OS) and disease-free survival (DFS) were assessed by log rank test and multivariable Cox regression analyses. Cumulative incidence functions were used to estimate recurrence, and groups were compared using Gray's test.

RESULTS

Of 775 patients, 650 had neoadjuvant chemoradiation and 125 had chemotherapy. These groups were comparable in terms of clinical tumour and lymph node categories, although the chemoradiation group had greater proportions of white men, complete pathological response to chemotherapy, and smaller proportions of diffuse cancer, poor differentiation, and neurovascular invasion. Postoperative major complications (20.0 versus 17.6 per cent) and 30-day mortality (1.7 versus 1.6 per cent) were not significantly different between the chemoradiation and chemotherapy groups. After adjustment, type of therapy (chemoradiation versus chemotherapy) was not significantly associated with OS (hazard ratio (HR) 1.26, 95 per cent c.i. 0.96 to 1.67) or DFS (HR 1.27, 0.98 to 1.64). Type of recurrence (local, regional, or distant) did not differ after neoadjuvant chemoradiation versus chemotherapy.

CONCLUSION

In patients undergoing surgical resection for locally advanced adenocarcinoma of the GOJ, OS and DFS did not differ significantly between patients who had neoadjuvant chemoradiation compared with chemotherapy.

Potential Molecular Targets in the Setting of Chemoradiation for Esophageal Malignancies

Although the development of effective combined chemoradiation regimens for esophageal cancers has resulted in statistically significant survival benefits, the majority of patients treated with curative intent develop locoregional and/or distant relapse. Further improvements in disease control and survival will require the development of individualized therapy based on the knowledge of host and tumor genomics and potentially harnessing the host immune system. Although there are a number of gene targets that are amplified and proteins that are overexpressed in esophageal cancers, attempts to target several of these have not proven successful in unselected patients. Herein, we review our current state of knowledge regarding the molecular pathways implicated in esophageal carcinoma, and the available agents for targeting these pathways that may rationally be combined with standard chemoradiation, with the hope that this commentary will guide future efforts of novel combinations of therapy.

Randomized, Phase II Study Prospectively Evaluating Treatment of Metastatic Esophageal, Gastric, or Gastroesophageal Cancer by Gene Expression of ERCC1: SWOG S1201

PURPOSE

Platinum-based therapy is the standard of care in patients who have HER2-negative, advanced esophagogastric cancer (AEGC). Retrospective data suggest that intratumoral ERCC1 levels may determine platinum sensitivity. A randomized, phase II study was performed in patients with AEGC to explore whether the efficacy of a platinum-based therapy with fluorouracil, leucovorin, and oxaliplatin (FOLFOX) versus a non-platinum-containing regimen of irinotecan and docetaxel (IT) differed according to ERCC1 levels.

PATIENTS AND METHODS

Overall, 202 untreated patients with HER2-negative AEGC and a Zubrod performance status of 0-1 were evaluated prospectively for mRNA expression of ERCC1 level and then randomly assigned to FOLFOX or IT, stratified by the intratumoral statuses of ERCC1 low (< 1.7) or high (≥ 1.7). Objectives were to assess progression-free survival (PFS) and overall survival (OS) in all patients treated with FOLFOX compared with IT, stratified by low and high ERCC1 levels, and to assess for interactive effects between ERCC1 expression and treatment arm.

RESULTS

Eighty-six percent of patients had ERCC1 values < 1.7. Thus, evaluation of the ERCC1-high subgroup was limited. Grade ≥ 3 anemia, dehydration, diarrhea, and fatigue were greater in patients with IT. Occurrences of grade ≥ 3 neuropathy and decreased neutrophils were greater in patients with FOLFOX. In all patients, FOLFOX had a statistically superior median PFS compared with IT (5.7 v 2.9 months; hazard ratio, 0.68; P = .02). In patients with ERCC1 levels < 1.7 receiving FOLFOX, PFS and response rate were statistically superior to IT, with no significant difference in OS.

CONCLUSION

The evaluation of ERCC1 in patients with upper GI tumors was thwarted by an overwhelming predominance of low ERCC1 mRNA expression. Nonetheless, distribution of treatment effects on PFS did not vary with expression. For all patients and for those with low ERCC1 expression, FOLFOX was superior in efficacy to IT.

Effect of the Addition of Cetuximab to Paclitaxel, Cisplatin, and Radiation Therapy for Patients With Esophageal Cancer: The NRG Oncology RTOG 0436 Phase 3 Randomized Clinical Trial

Importance

The role of epidermal growth factor receptor (EGFR) inhibition in chemoradiation strategies in the nonoperative treatment of patients with esophageal cancer remains uncertain.

Objective

To evaluate the benefit of cetuximab added to concurrent chemoradiation therapy for patients undergoing nonoperative treatment of esophageal carcinoma.

Design, Setting, and Participants

A National Cancer Institute (NCI) sponsored, multicenter, phase 3, randomized clinical trial open to patients with biopsy-proven carcinoma of the esophagus. The study accrued 344 patients from 2008 to 2013.

Interventions

Patients were randomized to weekly concurrent cisplatin (50 mg/m2), paclitaxel (25 mg/m2), and daily radiation of 50.4 Gy/1.8 Gy fractions with or without weekly cetuximab (400 mg/m2 on day 1 then 250 mg/m2 weekly).

Main Outcomes and Measures

Overall survival (OS) was the primary endpoint, with a study designed to detect an increase in 2-year OS from 41% to 53%; 80% power and 1-sided α = .025.

Results

Between June 30, 2008, and February 8, 2013, 344 patients were enrolled. This analysis used all data received at NRG Oncology through April 12, 2015. Sixteen patients were ineligible, resulting in 328 evaluable patients, 159 in the experimental arm and 169 in the control arm. Patients were well matched between the treatment arms for patient and tumor characteristics: 263 (80%) with T3 or T4 disease, 215 (66%) N1, and 62 (19%) with celiac nodal involvement. Incidence of grade 3, 4, or 5 treatment-related adverse events at any time was 71 (46%), 35 (23%), or 6 (4%) in the experimental arm and 83 (50%), 28 (17%), or 2 (1%) in the control arm, respectively. A clinical complete response (cCR) rate of 81 (56%) was observed in the experimental arm vs 92 (58%) in the control arm (Fisher exact test, P = .66). No differences were seen in cCR between treatment arms for either histology (adenocarcinoma or squamous cell). Median follow-up for all patients was 18.6 months. The 24- and 36-month local failure for the experimental arm was 47% (95% CI, 38%-57%) and 49% (95% CI, 40%-59%) vs 49% (95% CI, 41%-58%) and 49% (95% CI, 41%-58%) for the control arm (HR, 0.92; 95% CI, 0.66-1.28; P = .65). The 24- and 36-month OS rates for the experimental arm were 45% (95% CI, 37%-53%) and 34% (95% CI, 26%-41%) vs 44% (95% CI, 36%-51%) and 28% (95% CI, 21%-35%) for the control arm (HR, 0.90; 95% CI, 0.70-1.16; P = .47).

Conclusions and Relevance

The addition of cetuximab to concurrent chemoradiation did not improve OS. These phase 3 trial results point to little benefit to current EGFR-targeted agents in an unselected patient population, and highlight the need for predictive biomarkers in the treatment of esophageal cancer.

Trial Registration

clinicaltrials.gov Identifier: NCT00655876.

Adjuvant Chemoradiotherapy With Epirubicin, Cisplatin, and Fluorouracil Compared With Adjuvant Chemoradiotherapy With Fluorouracil and Leucovorin After Curative Resection of Gastric Cancer: Results From CALGB 80101 (Alliance)

Purpose After curative resection of gastric or gastroesophageal junction adenocarcinoma, Intergroup Trial 0116 (Phase III trial of postoperative adjuvant radiochemotherapy for high risk gastric and gastroesophageal junction adenocarcinoma: Demonstrated superior survival for patients who received postoperative chemoradiotherapy with bolus fluorouracil (FU) and leucovorin (LV) compared with surgery alone. CALGB 80101 (Alliance; Phase III Intergroup Trial of Adjuvant Chemoradiation After Resection of Gastric or Gastroesophageal Adenocarcinoma) assessed whether a postoperative chemoradiotherapy regimen that replaced FU plus LV with a potentially more active systemic therapy could further improve overall survival. Patients and Methods Between April 2002 and May 2009, 546 patients who had undergone a curative resection of stage IB through IV (M0) gastric or gastroesophageal junction adenocarcinoma were randomly assigned to receive either postoperative FU plus LV before and after combined FU and radiotherapy (FU plus LV arm) or postoperative epirubicin, cisplatin, and infusional FU (ECF) before and after combined FU and radiotherapy (ECF arm). Results With a median follow-up duration of 6.5 years, 5-year overall survival rates were 44% in the FU plus LV arm and 44% in the ECF arm ( P_logrank = .69; multivariable hazard ratio, 0.98; 95% CI, 0.78 to 1.24 comparing ECF with FU plus LV). Five-year disease-free survival rates were 39% in the FU plus LV arm and 37% in the ECF arm ( P_logrank = .94; multivariable hazard ratio, 0.96; 95% CI, 0.77 to 1.20). In post hoc analyses, the effect of treatment seemed to be similar across all examined patient subgroups. Conclusion After a curative resection of gastric or gastroesophageal junction adenocarcinoma, postoperative chemoradiotherapy using a multiagent regimen of ECF before and after radiotherapy does not improve survival compared with standard FU and LV before and after radiotherapy.

Prognostic significance of PET assessment of metabolic response to therapy in oesophageal squamous cell carcinoma

Objectives:

The role of maximum standard uptake value (SUVmax) at baseline and after induction chemotherapy (CT) on positron emission tomography (PET) as an imaging biomarker has not been well established in oesophageal squamous cell carcinoma (SCC). In this retrospective analysis, we investigated the prognostic significance of various PET metrics in oesophageal SCC patients treated with induction chemotherapy followed by concurrent chemoradiotherapy (CRT).

Methods:

A total of 57 patients were treated with CRT; 52 patients received induction chemotherapy and 10 patients underwent surgery following CRT. Scans were independently analysed by a nuclear medicine physician blinded to patient outcome. Using region of interest analysis, SUVmax and metabolic tumour volume (MTV) were calculated for the index lesion and lymph node metastases in each patient. Kaplan–Meier analysis was used to evaluate overall survival (OS), disease-free survival (DFS), local recurrence-free survival (LRFS) and distant metastasis-free survival (DMFS). Cox proportional hazards regression was used to assess correlation between outcomes and PET metrics.

Results:

Median follow-up for those who are alive was 4.4 years, with a median survival for all patients of 2.9 years. The 3-year OS, DFS, DMFS and LRFS rates were 47, 40, 44 and 36%, respectively. Using a pre-established cutoff of a 35% decrease in SUVmax from baseline to post-induction PET, 3-year OS for responders (⩾35% decrease from baseline) was 64%, whereas non-responders (<35% decrease from baseline) had a 3-year OS of 15% (P=0.004).

Conclusions:

The pre-specified 35% decrease in SUVmax after induction chemotherapy was prognostic for OS. Baseline and post-induction PET metrics provide prognostic information for oesophageal SCC.

Esophageal reinforcement with an extracellular scaffold during total gastrectomy for gastric cancer

BACKGROUND

Esophagojejunal (EJ) anastomotic leaks after total gastrectomy (TG) for malignancy lead to significant morbidity and mortality, thus affecting long-term survival. Preclinical and clinical trials have shown promise in utilizing degradable extracellular matrix (ECM) scaffolds in buttressing anastomoses. We describe our experience buttressing the EJ anastomosis after TG with a ECM scaffold.

METHODS

From February 2012 to January 2014, a total of 37 consecutive patients underwent TG buttressing of the EJ anastomosis with the degradable ECM scaffold composed of a porcine urinary bladder called MatriStem (ACell Inc.). The scaffold was circumferentially wrapped around the EJ anastomosis. The primary end point was the EJ leak rate, while the secondary end point was the EJ stricture rate.

RESULTS

The mean ± SD age and body mass index were 59 ± 16 years and 28.1 ± 4.9 kg/m(2), respectively. Most patients were male (51 %), white (78 %), and former smokers (51 %). Over half (59 %) underwent neoadjuvant chemotherapy. A minimally invasive TG was performed in 70 % of patients. Signet ring was the most common tumor type (48 %), and most patients had midstage disease (59 %). The mean number of lymph nodes procured was 36 ± 16. Eighteen patients (49 %) experienced a complication, mostly minor. One patient (2.7 %) developed an EJ leak, while three patients (8 %) developed an EJ stricture. Median follow-up was 7 months (range 2-12 months). There was no operative or in-hospital mortality.

DISCUSSION

The use of urinary bladder matrix scaffolds may be helpful in decreasing the incidence of EJ anastomotic leak and/or stricture. A prospective phase II trial at our institution is currently under way.

New directions in perioperative management of locally advanced esophagogastric cancer

Cancers of the esophagus arise as adenocarcinomas and squamous cell carcinomas; these represent distinct diseases, with differing prognosis, yet they are often studied in common trials. With surgery alone, 5 year survival for T2-T3N0 disease is less than 30% to 40%, and declines to less than 25% with nodal involvement. The CROSS randomly assigned patients to surgery alone or to weekly carboplatin/paclitaxel X 5 and 41.4 Gy concurrent radiotherapy, followed by surgery. Seventy-five percent of enrolled patients had adenocarcinoma. Preoperative combined-modality therapy improved R0 resection from 69% to 92% (p &lt; 0.001 and improved median survival from 24 months to 49.4 months (p &lt; 0.003). This regimen reduced both locoregional recurrence (34% to 14%; p &lt; 0.001) and the development of peritoneal carcinomatosis (14% to 4%; p &lt; 0.001). Systemic perioperative therapy may have a greater effect on distant disease, the predominant mode of failure for these patients, and current trials compare preoperative chemoradiation with periooperative systemic therapy. PET scan response during preoperative chemotherapy without radiotherapy correlates with improvements in pathologic response and with improved survival. Nonresponse on early PET scan allows identifıcation of patients for earlier surgery and discontinuation of ineffective preoperative chemotherapy, without survival detriment. There is no predictive benefıt for early PET scan during the course of chemotherapy followed by chemoradiotherapy. The use of early PET scan during induction chemotherapy is being evaluated in CALGB/Alliance trial (NCT01333033). Molecular profıling has identifıed somatic gene mutations and pathways that may be oncogenic in upper gastrointestinal cancers. Potential targets include the epidermal growth factor receptor (EGFR), vascular endothelial growth factor receptor (VEGFR), HER2, mammalian target of rapamycin (mTOR), fıbroblast growth factor receptor (FGFR), MEK, and others. Targeted therapies with known survival benefit in esophagogastric cancer are currently limited to trastuzumab for HER2 overexpressing cancers, or ramicirumab.

Phase II trial of sorafenib in esophageal (E) and gastroesophageal junction (GEJ) cancer: Response and prolonged stable disease observed in adenocarcinoma

91

Background: Sorafenib is a tyrosine kinase inhibitor targeting VEGFr, PDGFr, Raf and other pathways. Encouraging response and survival were observed in a phase II trial of sorafenib with chemotherapy in GE cancer (J Clin Oncol 27:2947;2010). We performed a phase II trial of single-agent sorafenib with the primary endpoint of progression-free survival (PFS). Secondary endpoints include response and toxicity. Methods: Patients (Pts) with measurable metastatic E and GEJ cancer with ≤3 prior chemotherapy regimens were treated with sorafenib 400 mg BID. CT scans were performed monthly for the first 2 months, then every 2 months. Results: Thirty-five patients have been accrued, with 34 evaluable; median age 62, 31 male, 4 female, median KPS 80%, E 25, GEJ 10, adenocarcinoma (AC) 30 squamous 5, median no. of prior therapies 2. Of 31 response-evaluable Pts, 1 (3%) ongoing complete response was noted (34+ months) in a Pt with E AC with biopsy-proven lymph node recurrence after chemoradiation and surgery; 23 Pts (74%) had stable disease. Median PFS is 3.7 months (95% CI 1.9 to 4 months), with median overall survival 8.9 months (95% CI 6.9 to 11.6 months). Four patients remain on treatment. Significant grade 3 toxicities included hand foot reaction (3 Pts), rash (1 Pt), dehydration (3 Pts) and fatigue (2 Pts). Twenty-seven of 33 tumors (82%) tested positive for phospho-ERK by immunohistochemistry. Conclusions: Encouraging activity in terms of PFS has been noted in this heavily pre-treated population. Updated data will be presented. Supported by a grant from Bayer. Clinical trial information: NCT00917462.

Phase II study of preoperative chemotherapy plus bevacizumab with early salvage therapy based on FDG-PET response in patients with locally advanced gastric and GEJ adenocarcinoma

94

Background: Response on FDG-PET scan during preoperative chemotherapy has prognostic significance. PET non-responders do poorly whether they continue the same chemotherapy or proceed directly to surgery [JCO 24: 4692; 2006, Lancet Onc 8:797;2007) Early identification of treatment failure using PET scan may spare patients (pts) from inactive therapy and allow for cross-over to alternative therapies. We performed a phase II trial to examine the effectiveness of FDG-PET directed early switching to salvage chemotherapy measured by 2 year disease free survival (DFS) in the PET non-responding group. Methods: Pts with PET avid, EUS and laparoscopically staged T3 or Node positive resectable gastric or GEJ adenocarcinoma received induction with epirubicin 50mg/m2, cisplatin 60mg/m2, capecitabine 625mg/m2 bid days 2-21(ECX) and bevacizumab 15mg/kg day 1. PET scan was repeated at week 3. PET responders (≥35% decline in SUV) continued ECX for 2 more cycles. PET non-responders switched to 2 cycles of salvage therapy: docetaxel 30mg/m2 d1, d8 q21 days, irinotecan 50mg/m2 d1, d8 q21 days and bevacizumab 15mg/kg day 1. Pts had surgery 4 weeks after cycle 3. Results: 20 of planned 60 pts were enrolled before the study closed for poor accrual. 14 male (64%), 8 female (39%), median age 62, median KPS 90. 11(55%) had a PET response after the first cycle. 10/11 (91%) underwent R0 resection: 1/10 pathologic CR, 3/10 pathologic PR. 9/20 PET non-responders switched to the salvage regimen. 7/9 Non-responders had R0 resection, none achieved a pathological response. The DFS for PET responders was 27.8mos (95% CI 10.3-27.8) and DFS in salvage group has not been reached. There was no significant difference in DFS between the two groups (p= 0.4). Follow up for overall survival is ongoing. Biologic correlative studies are pending. Conclusions: Response on PET scan during induction chemotherapy can identify early treatment failures. The results for therapy cross-over indicate a potentially improved DFS with salvage chemotherapy. Results from this trial are hypothesis generating and merit evaluation in a larger clinical trial. Supported by a grant from Genentech. Clinical trial information: NCT00737438.

Activity of front-line FOLFIRINOX (FFX) in stage III/IV pancreatic adenocarcinoma (PC) at Memorial Sloan-Kettering Cancer Center (MSKCC)

4057

Background: The PRODIGE/ACCORD trial recently established FFX as a treatment option for good performance status (PS) pts with stage IV PC (Conroy et al, NEJM 2011). We evaluated the activity and toxicity associated with FFX therapy in pts with advanced PC treated at MSKCC outside of a clinical trial. Methods: 80patients (pts) treated withFFX as 1st-line therapyat MSKCC between 07/1/10 and 12/30/11, were identified from an institutional database (prior IRB approval). Records were reviewed for demographic, treatment, toxcity, and response data. Results: 61 and 19 pts received FFX for stage IV and III PAC respectively. Demographics and outcomes are summarized in the table. Median starting dose of FFX was 80% of that used in the PRODIGE/ACCORD trial. Median overall survival (OS) was 12.5 months (mo) (95% CI 9.5–15.5) in pts treated with 1st line FFX for stage IV PAC and 13.7 mo (95% CI 11.3–15.8) in pts with stage III PAC. 68% of pts with stage IV PAC who discontinued FFX for disease progression (PD) or toxicity received 2nd-line gemcitabine-based therapy. Conclusions: We observed activity and acceptable toxicity in carefully selected patients treated with FFX at 80% dose intensity and routine use of growth factor support. Treatment with FFX resulted in median OS of > 1 year in pts with stage IV PAC and is an active front-line regimen. [Table: see text]

A phase II study of afatinib (BIBW 2992) in patients with advanced HER2-positive trastuzumab-refractory esophagogastric cancer

TPS4144

Background: Trastuzumab, approved by the FDA, has been the standard of care for patients (pts) with HER2-positive esophagogastric cancer. Acquired and de novo resistance to trastuzumab is an important clinical issue. Afatinib, an oral irreversible inhibitor of the ErbB-family of tyrosine kinase receptors, EGFR (ErbB1), HER2 (ErbB2), and HER4 (ErbB4), in combination with cetuximab, demonstrated a 40% partial response (PR) rate, with clinical benefit in >90% in lung cancer patients with acquired resistance to erlotinib. (Janjigian Y. ASCO 2011). MSKCC data in a HER2-positive NCI-N87 gastric cancer xenograft showed that while trastuzumab alone was minimally effective, single-agent afatinib resulted in near complete tumor regression by inducing apoptosis and downregulation of HER2, p-HER2, EGFR, p-EGFR with minimal additive benefit of trastuzumab. In light of these data and the efficacy of afatinib in patients with trastuzumab-refractory breast cancer, we designed a phase II study to determine if afatinib will benefit patients with trastuzumab-refractory HER2-positive esophagogastric cancer. We hypothesize that simultaneous inhibition of ErbBB receptor family components with afatinib will overcome trastuzumab resistance. Molecular bases of trastuzumab resistance will be examined. Methods: Pts with metastatic HER2-positive (IHC 3+ or FISH >2.0) esophagogastric cancer with disease progression on a trastuzumab-containing regimen will receive afatinib 40 mg once daily. Primary endpoint RECIST 1.1 response (SD+CR+PR) at 4 months, with imaging every 8 wks. 13 pts will be enrolled in the 1st stage and if ≥1 responses are observed, additional 14 ps (total of 27) will be treated. An initial biopsy prior to the start of therapy, a second biopsy after 1 wk of afatinib, analysis of archival pre-trastuzumab tissue and blood sample for matched normal DNA control are mandated. Changes in signaling following afatinib therapy will provide insight into response heterogeneity. Degree of target inhibition will be correlated with responses. Archival baseline (pre-trastuzumab) and pre-afatinib tissue will be assessed for abnormalities in pathways implicated in trastuzumab resistance.

Phase II trial of bevacizumab, irinotecan, cisplatin, and radiation as preoperative therapy in esophageal adenocarcinoma

4061

Background: Preop chemo and radiotherapy (RT) with weekly irinotecan (I), cisplatin (C) and 5040 cGy is tolerable and active [Cancer, in press]. Bevacizumab (B) + weekly I/C in advanced esophagogastric cancer increased response rate and PFS without an increase in toxicity [JCO 24: 5201; 2006]. In a phase II trial in esophageal adenocarcinoma (EA) we combed B + I/C with RT as preop therapy. A toxicity analysis after 10 patients (pts) undergoing surgery indicated no unexpected toxicity with B [JCO 27: Abstract 4573; 2009], and we completed a planned accrual of 33 pts. Methods: Pts had resectable distal esophageal or Siewert’s I or II EA, T2-3 or N1 staged by EUS, PET, and CT scan. Induction chemo: I: 50-65 mg/m2 + C: 30 mg/m2 weeks 1,2,4,5, B: 7.5 mg/kg weeks 1 and 4; Chemort: 180 cGy daily fractions to 5040 cGy, I/C weeks 7,8,10,11+ B weeks 7,10. Esophagectomy was planned 6-8 weeks after RT. Postop: B: 7.5 mg/kg every 3 weeks for 8 cycles. Results: 33 pts were enrolled. 26 male: 7 female; distal esophagus 11 (33%), GEJ 22 (67%); 21 T3N1 (64%); 10 T3N0 (30%); 2 T2N0-1 (6%). 25/33 pts went to surgery (76%), 24 had R0 resection (73%). Pathologic CR 5 pts (15%). 8 pts did not going to surgery: 2 for adverse events (9%, 1 CVA due to patent foramen ovale, 1 esophageal perforation due to endoscopic biopsy), 6 for progressive disease (18%). 21/24 pts (88%) received adjuvant B, 20 (95%) completed all cycles. Grade 3/4 toxicity in 30 evaluable pts during chemort: 24% neutropenia, 3% neutropenic fever, 23% esophagitis, 13% dehydration, 13% thrombocytopenia, 7% pulmonary embolism, 3% nausea/vomiting. Surgical complications: 3 anastomotic leaks (12%), 4 respiratory failure (16%), 1 pulmonary embolism (4%), 2 post op deaths (8%). At a median follow up of 20 months, PFS was 14 months and OS was 30 months. Conclusions: The addition of B to preop chemoRT in EA was tolerable without increase in treatment toxicity or surgical complications. There was no suggestion of improved pathologic CR, PFS, or OS with the addition of B to I/C/RT. Evaluation of B in phase III trials of chemort does not appear warranted. Supported by a grant from Genentech.

Phase II trial of bevacizumab, irinotecan, cisplatin, and radiation as preoperative therapy in esophageal adenocarcinoma

67

Background: Preop chemo and radiotherapy (RT) with weekly irinotecan (I), cisplatin (C) and 5040 cGy is tolerable and active [Cancer, in press]. Bevacizumab (B) + weekly I/C in advanced esophagogastric cancer increased response rate and PFS without an increase in toxicity [JCO 24: 5201; 2006]. In a phase II trial in esophageal adenocarcinoma (EA) we combined B + I/C + RT as preop therapy. A toxicity analysis after 10 patients (pts) undergoing surgery indicated no unexpected toxicity with B [JCO 27: Abstract 4573; 2009]. We completed a planned accrual of 33 pts.

Methods: Pts had resectable Siewert’s I or II EA, T2-3 or N1 staged by EUS, PET, and CT scan. Induction chemo: I 50-65 mg/m2 + C 30 mg/m2 weeks 1,2,4,5, B 7.5 mg/kg weeks 1 and 4; Chemort: 180 cGy daily fractions to 5040 cGy, I/C weeks 7,8,10,11+ B weeks 7,10. Esophagectomy was planned 6-8 weeks after RT. Postop: B 7.5 mg/kg every 3 weeks for 8 cycles.

Results: 33 pts were enrolled. 26 male: 7 female; 13 Siewert I (39%): 20 Siewert II (61%); 21 T3N1 (64%); 10 T3N0 (30%); 2 T2N0-1 (6%). 25/33 pts went to surgery (76%), 24 had R0 resection (73%). Pathologic CR 4/33 pts (12%). 8 pts did not go to surgery: 2 for adverse events (9%, 1 CVA due to patent foramen ovale, 1 esophageal perforation due to endoscopic biopsy), 5 for progressive disease (15%). 21/24 pts (88%) received adjuvant B, 20 (95%) completed all cycles. Grade 3/4 toxicity in 30 evaluable pts during chemort: 27% neutropenia, 3% neutropenic fever, 23% esophagitis, 13% dehydration, 13% thrombocytopenia, 7% pulmonary embolism, 3% nausea/vomiting. Surgical complications: 3 anastamotic leaks (12%), 4 respiratory failure (16%), 1 pulmonary embolism (4%), 2 post op deaths (8%). At a median follow up of 20 months, PFS was 14 months and OS was 30 months.

Conclusions: The addition of B to preop chemoRT in EA was tolerable without increase in treatment toxicity or surgical complications. There was no suggestion of improved pathologic CR, PFS, or OS with the addition of B to I/C/RT. Evaluation of B in phase III trials of chemort does not appear warranted. Supported by a grant from Genentech.

Phase II study of ganetespib, an hsp-90 inhibitor, in patients with refractory metastatic colorectal cancer

467

Background: To evaluate the safety and efficacy of ganetespib, a heat shock protein 90 (Hsp90) inhibitor, as monotherapy in patients with refractory metastatic colorectal cancer.

Methods: A phase II study utilizing a two-stage design was performed in which patients received Ganetespib 200 mg/m2 intravenously (IV) one time per week for three weeks followed by a one week break. Patients underwent pre and 48 hour post treatment tumor biopsies. Immunohistochemistry (IHC) was performed for p/Erk, CyclinD1, p/Akt, HIF-1a, VEGFr2 , p70S6 and Hsp70. Archived and pre dose biopsy tissue was utilized for KRAS, BRAF and PIK3CA genotyping using a Sequenom platform.

Results: Fifteen patients were treated (median age 58, range 44-79). There were no responders. Two patients had stable disease lasting 31 and 23 weeks. The most frequent grade 1/2 toxicities were diarrhea, fatigue, nausea/vomiting and elevated transaminases ( Table ). These complications did not result in any treatment interruption. The most frequent grade 3 adverse events were diarrhea (12%), fatigue (24%), and elevated AST(12%) and Alk phos(29%). Three (20%) patients required dose reductions, 1 grade 3 AST, 1 grade3 ALT and 1 grade 3 fatigue.

Conclusions: This was the first study of an Hsp90 inhibitor in colorectal cancer. Ganetespib treatment did not produce tumor responses when administered as a single agent in refractory metastatic colorectal cancer with this dosing regimen. Overall the drug was well tolerated and the toxicity profile was minimal. Ganetespib may be used in combination in future studies. Correlative IHC analyses will be presented.

[Table: see text]

Phase II trial of sorafenib in esophageal (E) and gastroesophageal junction (GEJ) cancer: Response observed in adenocarcinoma

41

Background: Sorafenib is a tyrosine kinase inhibitor targeting VEGFr, PDGFr, Raf and other pathways. Encouraging response and survival were observed in a phase II trial combining sorafenib with chemotherapy in GE cancer (J Clin Oncol 27:2947;2010). We are studying single agent sorafenib in a phase II trial with the primary endpoint to assess progression free survival (PFS). Secondary endpoints include response and therapy tolerance.

Methods: Patients (pts) with measurable metastatic E and GEJ cancer with no more than 3 prior chemotherapy regimens were treated with sorafenib 400 mg BID. CT scans were performed monthly for the first 2 months, then every 2 months.

Results: Sixteen of 35 pts have been accrued and 14 are currently evaluable. 13 male, 3 female, median KPS 80%, age 58, GEJ 7, E 9, squamous 2, adenocarcinoma (AC)14. An ongoing complete response (11+ months) was observed in a pt with biopsy proven metastatic neck lymphadenopathy (E primary AC, recurrence after prior chemoradiotherapy and surgery). A second pt (GEJ AC) had protracted stable disease in bulky celiac node disease (15+ months). Grade 3 toxicity was limited to skin rash (1 pt), hand foot reaction (1 pt), and fatigue (1 pt). Only 3 of 14 pts (21%) had early disease progression at 2 months or less. Median PFS 4 mos, 4 patients (29%) continue on therapy for more than 7 months. The majority of tumors tested positive for phospho-erk by immunohistochemistry (11/14, 79%).

Conclusions: The observation of a durable complete response and protracted stable disease to sorafenib in E cancer is remarkable. Further accrual continues to define PFS. Supported by a grant from Bayer.

[Table: see text]

Integrated safety findings with tesetaxel, an orally administered taxane, in patients (pts) with gastric, colon, breast, and nonsmall cell lung cancer: Phase II results

e13516

Background: The orally active taxane tesetaxel has potent cytotoxic activity against various human and murine cancer cell lines in vitro and in xenograft tumor models, including those that express P-glycoprotein (pgp). In a Phase 1 study, 48 pts with advanced solid tumors were treated at doses of 1.5 mg/m2 to 40 mg/m2. AUC and Cmax increased in a dose-proportional manner. There was no dose-limiting toxicity (DLT) at doses ≤18 mg/m2. Above 18 mg/m2, Grade 4 neutropenia > 5 days in duration was the most common DLT. The MTD was 27 mg/m2 for heavily pretreated pts and 35 mg/m2 for minimally pretreated pts. These doses were further evaluated in a Phase 2 program in 4 studies, and activity was demonstrated in gastric, colorectal, breast, and non-small cell lung cancers. To assess safety across all indications prior to beginning randomized trials, we conducted an integrated analysis of the safety of the 27 mg/m2 dose as initial therapy in Phase 2. Methods: All pts had been previously treated with a nontaxane regimen. Tesetaxel was given on Day 1 of a 21-day cycle; the dose was rounded to the nearest 10 mg. Prophylactic treatment with such drugs as antiemetics and colony- stimulating factors (CSFs) was permitted only after Cycle 1. Results: A total of 142 subjects received tesetaxel 27 mg/m2 as initial therapy. The most common Grade 3–4 adverse events were neutropenia (33%), leukopenia (22%), and anemia (11%). Grade 3–4 neuropathy was distinctly uncommon (3%). Conclusions: Taxanes are highly active in solid tumors, but most are associated with neurotoxicity and infusion reactions. Oral tesetaxel eliminates infusion reactions and consequent requirements for extended observation and premedication, is associated with a low incidence of Grade 3–4 neurotoxicity, and may be useful in diseases associated with high pgp expression. Like other taxanes, the most common adverse event is neutropenia, which can be ameliorated with appropriate monitoring and use of CSFs. These and other safety considerations will be incorporated into planned registration trials.

[Table: see text]

Phase II trial of preoperative bevacizumab (Bev), irinotecan (I), cisplatin (C), and radiation (RT) in esophageal adenocarcinoma: Preliminary safety analysis

4573

Background: Preo chemoRT with weekly I/C and 5040 cGy followed by surgery is well tolerated [JCO 24: Abstract 4032; 2006]. ECOG trial E1201recently reported a median survival of 34 months with this preop regimen [JCO 26: Abstract 4532; 2008]. Bev + chemo improves response rate (RR) and time to progression (TTP) when added to weekly I/C in advanced esophagogastric cancer but does not increase chemo toxicity [JCO 24: 5201; 2006]. We are now combining in a Phase II trial Bev/I/C with concurrent radiotherapy (RT) in esophageal adenocarcinoma (EA) with the primary endpoint of safety. Methods: Patients (pts) with resectable Siewert's I or II EA were staged by EUS, PET, and CT. Induction chemo consisted of I-50–65 mg/m2 and C-30 mg/m2 weeks 1,2,4,5, Bev-7.5 mg/kg weeks 1 and 4; and, during RT (180 cGy daily to 5040 cGy), I/C was given weeks 7,8,10,11 and Bev weeks 7,10. Esophagectomy was 6–8 weeks after RT. A planned toxicity analysis was made in 10–15 pts completing chemoRT, and in 10 pts undergoing surgery: toxicity was acceptable if grade 3 / 4 hematologic toxicity remained < 72% and non hematologic toxicity < 40% during combined chemoRT (based on our prior phase II trial of I/C/RT [JCO 24: Abstract 4032; 2006]); and if pts undergoing surgery had no surgical complication related to Bev. Results: 18 pts have been enrolled, 12 male: 6 female; 7 Siewert I: 11 Siewert II; T3N1 12: T3N0 5: T2N0 1. 14 are evaluable for toxicity, 2 are too early, one progressed prior to RT, and one was taken off due to a CVA from a patent foramen ovale. Grade 3/4 neutropenia occurred in 4 pts (29%). Grade 3/4 non heme toxicity occurred in 5 pts (36%), including esophagitis 2 pts (14%), neutropenic fever 1 pt (7%), and pulmonary embolism 1 pt (7%). No grade 3 / 4 hypertension was seen, and 3 pts (21%) developed grade 1 proteinuria. Ten pts underwent surgery, and there were no unexpected surgical or wound complications; there were 2 anastomotic leaks. Pathologic responses: 1 pathologic CR and 1 T0N1. Conclusions: In a preliminary analysis of pts treated with Bev + preop chemoRT in EA, there was no increase in hematologic/non hematologic toxicity or Bev related surgical complications. Accrual will continue to 33 patients. Supported by Genentech.

[Table: see text]

Analysis of survival with modified docetaxel, cisplatin, fluorouracil (mDCF), and bevacizumab (BEV) in patients with metastatic gastroesophageal (GE) adenocarcinoma: Results of a phase II clinical trial

4512

Background: Metastatic GE cancer is an aggressive disease with poor patient (pt) outcomes. Despite response rates of 30–60% to combination chemotherapy, response duration is usually 4–6 mo and 24-mo survival is 5–10%. The addition of BEV to chemotherapy has improved survival in several solid tumors, and has demonstrated encouraging activity in GE cancer (Shah et al, JCO 2006). We report mature tolerability and efficacy results of mDCF+BEV in GE cancer, with an emphasis on prolonged pt survival. Methods: Previously untreated metastatic GE pts with adequate end organ function received BEV 10mg/kg, Docetaxel 40mg/m2, FU 400mg/m2, Leucovorin 400mg/m2 on day 1, FU 1000 mg/m2/day x 2 days IVCI, and Cisplatin 40mg/m2 on day 3. Treatment is repeated every 14 days without prophylactic growth factor support. The primary objective is to improve 6-month progression free survival (PFS) from 43% (historical DCF control) to 63% with the addition of BEV. Target accrual is 44 evaluable pts, with 10% type I & II error. Secondary objectives include tolerability, response rates (RECIST), median PFS, 12-mo survival, and overall survival (OS). Results: Pt enrollment has completed: median age 57(range 29–74), median KPS 80% (70–100), M:F 32:12, gastric/GEJ/esophagus 22:17:5. In 39 patients with measurable disease we observed 26 confirmed partial responses (67%, 95% CI 50%- 81%), and 12 (31%) stable disease. Six-month PFS is 79% (95% CI 68%-93%), the median PFS is 12 mo (95% CI: 8.8–16). At median follow up of 12.3 mo, median OS is 16.2 mo (95%CI 11.4-infinitiy). 12- and 18-mo OS is 63% (95%CI 44–77%) and 46% (95%CI 27–63%), respectively. Minimal chemotherapy related grade 3–4 adverse events were observed: fatigue (20%), dehydration (13%), mucositis (9%), nausea/vomiting (7%), febrile neutropenia (4%). BEV related adverse event was perforation (n=1) and bleeding (n=1). 31% developed grade 3–4 venous thromboembolism, of which 93% were asymptomatic. No grade 3–4 hypertension, proteinuria or arterial thrombosis was observed. Conclusions: mDCF+BEV appears tolerable and has notable long term pt outcomes: 6-mo PFS is 79% (surpassing our efficacy endpoint), median OS 16.2 mo, and 18-mo OS 46%.

No significant financial relationships to disclose.

European Organisation of Research and Treatment of Cancer (EORTC) Gastrointestinal Group: Workshop on the role of metabolic imaging in the neoadjuvant treatment of gastrointestinal cancer

Metabolic imaging and early response assessment by positron emission tomography (PET) are gaining importance in guiding treatment of localised and metastatic gastrointestinal tumours. During a workshop organised by the European Organisation of Research and Treatment of Cancer (EORTC) Gastrointestinal Tract Cancer Group the most relevant research questions, methodological aspects and unmet clinical needs in this disease were discussed. Potential future trials were drafted. This paper reviews the lectures and discussions held during this workshop and summarises the action points for the further investigation of metabolic imaging to guide treatment in gastrointestinal tumours.

Volumetric 3D CT analysis - an early predictor of response to therapy

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Background: Evidence suggests that changes in unidimensional measurements (using RECIST criteria) may not accurately reflect actual changes in tumor size, and do not correlate well with other biomarkers of response, tumor progression, or patient outcome. We evaluated changes in tumor volume of target lesions with volumetric CT, and compared them with response assessments derived from RECIST criteria. Methods: We evaluated target lesions, including lymph node, liver, peritoneal and lung metastases in 25 patients with metastatic gastric cancer or gastroespohageal junction adenocarcinoma treated on a phase II clinical trial with irinotecan, cisplatin and bevacizumab. All patients underwent thin-section multidetector CT at baseline and 6-week follow-up for 10 cycles. Target lesions were measured unidimensionally and volumetrically, using validated automated and semiautomated segmentation algorithms. For initial analysis, correlation was made with the RECIST response using a cut-off value of 65% volume change. A ratio of change in RECIST measure to volume measure was calculated at time of maximal clinical response for each patient, as well as for responders versus non-responders. Results: 18 of 25 (72%) patients showed a clinical response. Of these 18 responders, 5, 6, 4, and 3 were identified as responders using RECIST criteria after cycles 1, 2, 3, and 4, respectively. Using a cut-off of 65% volume change, 14 of these responders were indentified after cycle 1, and 4 were identified after cycle 2. Using a cut-off value of 65%, volume measurements identified responders a mean of 50.3 days earlier than did RECIST criteria. There was a statistically significant (p<0.01) change in ratio of volume measurement change to RECIST measurement change for responding versus stable patients. Conclusions: Volumetric change in tumor size appears to predict clinical response earlier than do RECIST criteria in the majority of cases. Changes in volume are more sensitive because they exhibit a wider dynamic range. Ratios of size changes volumetrically appears to better discriminate RECIST responders from those with stable disease. Further work is needed to define the biologically relevant cut-off value for volume change, and to correlate volume change with other biomarkers.

No significant financial relationships to disclose.