Combined HER2 analysis of biopsies and surgical specimens to optimize detection of trastuzumab-eligible patients in eso-gastric adenocarcinoma: a GERCOR study

BACKGROUND

HER2 is overexpressed in 10 to 20% of gastro-esophageal adenocarcinoma (GE-ADK), and is a target for trastuzumab in metastatic patients. We conducted a study to compare HER2 expression between diagnostic biopsies (DBs) and surgical specimens (SSs) of GE-ADK, and to determine the influence of non-trastuzumab containing neoadjuvant chemotherapy (NAC) on this expression.

PATIENTS AND METHODS

Pathological specimens from biopsies of 228 patients operated on between 2004 and 2011 were collected. Two cohorts treated (n = 141) or not (n = 87) with a NAC were constituted. Two blind independent pathological HER2 analyses on DB and on SS were carried out using immunohistochemistry (IHC) and colorimetric in situ hybridization (CISH). HER-2 overexpression (HER2+) was defined by a score 3+ in IHC, or 2+ with a positive CISH test, according to the specific HER2 scoring guidelines for GE-ADK.

RESULTS

Paired HER2 status could be determined for 218 out of the 228 patients (95.6%). HER2+ rates were 13.3% on DB (29/218) and 14.7% on SS (32/218). HER2+ tumors were mainly cardial or esophageal adenocarcinomas, with a well-differentiated, intestinal histological type. HER2 status differed between DB and SS in 6% of cases. When DB analyses were added to SS analyses, the relative increase in HER2+ cases was 13.5% (17.1% for patients with NAC and 23.5% for patients with histological response to NAC, versus 7.1% for patients without NAC, P = 0.4, NS). Differences between DB and SS HER2 expression could be explained by intratumoral heterogeneity and by a HER2 expression decrease in SS after NAC in responding patients possibly due to a higher chemosensitivity of HER2-positive clones.

CONCLUSION

The determination of HER2 status on DB provides results that complete those obtained with SS. Combining the analysis of DB and of SS enables to optimize the selection of trastuzumab-eligible patients in case of metastatic relapse, and particularly in previously NAC-responding patients.

Panitumumab combined with irinotecan for patients with KRAS wild-type metastatic colorectal cancer refractory to standard chemotherapy: a GERCOR efficacy, tolerance, and translational molecular study

BACKGROUND

The purpose of this study was to evaluate the combination of panitumumab and irinotecan in patients with KRAS wild-type metastatic colorectal cancer refractory to standard chemotherapy (oxaliplatin, fluoropyrimidines-irinotecan and bevacizumab).

PATIENTS AND METHODS

KRAS status was first determined locally but subsequent validation of KRAS status and additional screenings (rare KRAS, NRAS, BRAF mutations and EGFR copy number) were centrally assessed. Patients received panitumumab (6 mg/kg) and irinotecan (180 mg/m²) every 2 weeks.

RESULTS

Sixty-five eligible patients were analyzed. The objective response rate (ORR) was 29.2% [95% confidence interval (95% CI) 18.2-40.3]. Median progression-free and overall survivals were 5.5 and 9.7 months, respectively. Most frequent grade 3/4 toxic effects were skin 32.3%, diarrhea 15.4% and neutropenia 12.3%. Tissue samples were available for 60 patients. For the confirmed KRAS wild-type population codon 12 or 13 mutation (n = 54), ORR was 35.2% (95% CI 22.4.1-47.9). Thirteen patients had a NRAS, a BRAF or a rare KRAS mutation, and no tumor response was observed in this subgroup when compared with 46.3% (95% CI 31.1-61.6) ORR in the subgroup of 41 patients with no identified mutation.

CONCLUSION

Panitumumab and irinotecan is an active third-line regimen in a well-defined population based on biomarkers. ClinicalTrials.gov Identifier NCT00655499.

Prognostic impact of microsatellite instability in colorectal cancer patients treated with adjuvant FOLFOX

BACKGROUND

Colorectal cancer (CRC) patients whose tumours have microsatellite instability (MSI) do not benefit from adjuvant 5-fluorouracil. However, the predictive value of MSI is not known for FOLFOX, now recommended in adjuvant setting.

PATIENTS AND METHODS

MSI phenotype was assessed by the pentaplex method. Three-year relapse and disease-free survival (DFS) of patients treated for CRC with FOLFOX 4 in an adjuvant setting were compared according to MSI phenotype.

RESULTS

A total of 105 patients (19 MSI, 86 microsatellite stable, MSS) were included. Stage II patients more frequently exhibited MSI (58%) than MSS (21%); (p=0.002). Patients with MSI relapsed significantly less than those with MSS (10.5% vs. 35.0%; p=0.04). DFS was similar for MSI and MSS (p=0.1). In univariate analysis, stage (p=0.0006) and MSI status (p=0.017) were significant predictors of DFS.

CONCLUSION

MSI status was associated with significantly fewer relapses and a better prognosis. FOLFOX4 did not alter survival of patients with MSI and can be administered to them.

Preoperative treatment combining capecitabine with radiation therapy in rectal cancer: a GERCOR Phase II Study

OBJECTIVE(S)

To assess efficacy and tolerability of preoperative capecitabine chemoradiation in rectal cancer.

METHODS

Patients received radiotherapy 45 Gy in 25 fractions over 5 weeks and capecitabine 825 mg/m(2) twice daily throughout radiotherapy. Surgery was performed 5-7 weeks after radiotherapy. The primary endpoint was pathological complete response, secondary endpoints were downstaging and tolerability.

RESULTS

Fifty-one patients were enrolled in a phase II study, median age 62 years (range 35-78). Sixty-three percent of tumours involved the lower third of the rectum, 45% were fixed. The median delivered radiotherapy dose was 44.8 Gy (range 39.6-45.0 Gy) over 33-49 days. The treatment-related grade 3 adverse events were diarrhoea (12%), skin reactions (8%) and asthenia (8%), with no grade 4 toxicity. Fifty patients underwent surgery (29 conservative) and 1 patient refused. The pathological complete response rate was 20% and a further 10% of patients had minimal residual disease. Additional tumour downstaging was seen in 28% of patients and the sphincter preservation rate was 58%.

CONCLUSIONS

Preoperative capecitabine chemoradiation is well tolerated and its efficacy supports further exploration, both as a single agent and as part of new therapeutic strategies.

Final results of OPTIMOX2, a large randomized phase II study of maintenance therapy or chemotherapy-free intervals (CFI) after FOLFOX in patients with metastatic colorectal cancer (MRC): A GERCOR study

4013

Background: The OPTIMOX2 study was designed to evaluate a complete stop of chemotherapy after 6 bimonthly cycles of FOLFOX. Methods: OPTIMOX2 is a large phase II study performed before the availability of bevacizumab. Patients (pts) were randomized between an OPTIMOX1 arm: 6 cycles of FOLFOX7 followed by LV5FU2 until progression then reintroduction of FOLFOX7, and the OPTIMOX2 arm: 6 cycles of FOLFOX7, complete stop of chemotherapy and reintroduction of FOLFOX7 before the tumor progression reached the baseline measures. Results: 202 pts were included between Feb 2004 and Apr 2006. Response rates were (OPTIMOX1/OPTIMOX2): CR+PR 63%/61%. Median PFS were OPTIMOX1/OPTIMOX2) 8.3/6.7 months (p=.04). Median duration of disease control (DDC), addition of PFS of first FOLFOX7 administration plus PFS of FOLFOX reintroduction if no progression at first evaluation, was 10.8m in the OPTIMOX1 arm and 9.0m in the OPTIMOX2 arm, p=.32. Median duration of chemotherapy-free interval (CFI) in the OPTIMOX2 arm was 4.6 months. Patients with poor prognostic factors had a shorter CFI, p=.01. Median overall survival was 24.6m in the OPTIMOX1 arm and 18.9m in the OPTIMOX2 arm, p=.05. Median survivals (OPTIMOX1/OPTIMOX2) were not reached/28.7m in patients with good prognostic and 20.9/14.5m in patients with poor prognostic. Conclusions: Maintenance LV5FU therapy prolongs PFS and OS, especially in patients with poor prognosis. CFI can be recommended only in selected patients without adverse prognostic factors. Our next study, DREAM, is evaluating maintenance therapy with targeted agents alone.

No significant financial relationships to disclose.

Antitumour activity of pemetrexed (Pem) and irinotecan (Iri) in second-line metastatic colorectal cancer (MCRC) patients: A multicenter phase II study

4103

Introduction: 5FU + Iri (i.e. FOLFIRI) is a validated second line treatment after 5FU + Oxaliplatin (i.e. FOLFOX) induction in MCRC, with a response rate ranged from 10 to 15%. Pem is a multi-antifolate with wide range of target inhibition as compared to 5FU suggesting that Pem + Iri could have a better efficacy as compared to FOLFIRI. We then studied the antitumour activity and the safety of Pem + Iri combination in patients treated with FOLFOX for MCRC. Methods: Forty-six patients with measurable second line MCRC and no brain metastases were included in this trial. Pem 400 mg/m2 over 10min on d1 with folic acid and vitamin B12 supplementation followed by Iri 180 mg/m2 (90min) on the same day were given q2w for 12 cycles. Results: 44/46 patients (95%) received at least one cycle of the combination with median age: 63 yrs, baseline ECOG performance status = 2: 100%. Metastatic sites were: liver: 70%, lung: 41%, lymph node: 7% and peritoneum: 5%. The median number of administered cycles was 4.5. Seven out of 44 patients (16%) received at least 12 cycles of study therapy. The objective response rate (intent-to-treat, RECIST criteria, assessed by investigators) was 14% (95% CI [5.2; 27.4]), 41% had stable disease. Grade 3/4 toxicities were: neutropenia: 19%, anemia: 9%, elevated AST/ALT 10%, diarrhea: 16%, vomiting: 7%, nausea: 5% and fatigue: 20% which was the most limiting toxicity for this combination. Conclusion: The combination of Pem + Iri is active in second line MCRC. However, response rate seems to be in the same range as compared to historical data for FOLFIRI. Patients are still in the follow-up period. Data of PFS and OS will be presented at the meeting.

No significant financial relationships to disclose.

Role of MSI and DCC status to predict response to FOLFOX in metastatic colorectal cancer

21056

Background: Microsatellite instability (MSI) and lack of Deleted Colon Cancer (DCC) protein expression have been observed respectively in ∼15% and 70% of colon cancer cases and are considered as prognostic factors in colorectal cancer (CRC). In adjuvant setting these markers could be considered to decide treatment. We know that MSI colon cancer do not benefit from 5Fluorouracyl (5FU)-based chemotherapy. A current treatment of reference for colon cancer is a combination of 5FU and Oxaliplatin (FOLFOX). Our aim was to determine whether MSI status or DCC expression are predictive markers of FOLFOX efficiency in patients with metastatic CRC. Methods: Tumour specimens were collected from patients with metastatic colon cancer treated with FOLFOX. The FOLFOX regimen was evaluated in first line treatment according to the WHO criteria. The microsatellite instability status was assessed by measurement of the length of five monomorphic mononucleotide markers. DCC protein expression were evaluated by immunohistochemistry. Results: Forty patients (22 men, 18 women), median age 63.5 years (27–83) were treated with FOLFOX. Nine patients had tumours exhibiting high microsatellite instability (microsatellite instability group, MSI group) and 31 patients had tumours exhibiting microsatellite stability (microsatellite stable group, MSS group). In MSS group, we observed 11 partial responses (36%) and only two in MSI group (22%) (not significant difference). Both disease free survival and overall survival were not significantly different for MSI and MSS groups. Determination of DCC status is under investigation. Conclusions: There was no significant difference in chemosensitivity to FOLFOX for MSI and MSS metastatic patients. Therefore FOLFOX regimen could be proposed to metastatic patients irrespective of MSI status. The study of the relationship between DCC expression and response to FOLFOX is ongoing.

No significant financial relationships to disclose.

OPTIMOX2, a large randomized phase II study of maintenance therapy or chemotherapy-free intervals (CFI) after FOLFOX in patients with metastatic colorectal cancer (MRC). A GERCOR study

3504

Background: The OPTIMOX1 study (JCO 2006) has shown that the strategy of 6 cycles of FOLFOX7 followed by maintenance therapy and FOLFOX reintroduction was as active and better tolerated than FOLFOX4 until progression. The aim of the OPTIMOX2 study was to evaluate a complete stop of chemotherapy after 6 bimonthly cycles of FOLFOX. Methods: Initially planned as a phase III study, OPTIMOX2 was downgraded to a large phase II study since the availability of bevacizumab. Patients (pts) were randomized between an OPTIMOX1 arm: 6 cycles of FOLFOX7 followed by LV5FU until progression and reintroduction of FOLFOX7, and the OPTIMOX2 arm: 6 cycles of FOLFOX7, complete stop of chemotherapy and reintroduction of FOLFOX7 before the tumor progression reached the baseline measures. Results: 187/200 planned pts were included between Feb 2004 and Nov 2005. Response rates were (OPTIMOX1 arm/OPTIMOX2 arm): CR 2%/2%, PR 54%/51%, stable 24%/33%, progression 11%/7%, non assessable 9%/7%. Median PFS were (OPTIMOX1 arm/OPTIMOX2 arm) 36/28 weeks (p=.01), PFS in responders 41/30 weeks (p=.001), PFS in stable patients 34/26 weeks (p=.23). Median duration of disease control (DDC), addition of PFS of first FOLFOX7 administration plus PFS of FOLFOX reintroduction if no progression at first evaluation, was 41 weeks in the OPTIMOX1 arm and 36 in the OPTIMOX2 arm, p=.17. Median duration of chemotherapy-free interval in the OPTIMOX2 arm was 25 weeks (5.7 months). Conclusions: Maintenance LV5FU therapy prolongs PFS. The quality of life of almost 6 months CFI can balance a small advantage in DDC for maintenance therapy. Our next goal is to evaluate maintenance therapy with targeted agents alone.

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A structural-description-based vision system for automatic object recognition

This paper presents the results of the integration of a proposed part-segmentation-based vision system. The first stage of this system extracts the contour of the object using a hybrid first- and second-order differential edge detector. The object defined by its contour is then decomposed into its constituent parts using the part segmentation algorithm given by Bennamoun (1994). These parts are then isolated and modeled with 2D superquadrics. The parameters of the models are obtained by the minimization of a best-fit cost function. The object is then represented by its structural description which is a set of data structures whose predicates represent the constituent parts of the object and whose arguments represent the spatial relationship between these parts. This representation allows the recognition of objects independently of their positions, orientations, or sizes. It is also insensitive to objects with partially missing parts. In this paper, examples illustrating the acquired images of objects, the extraction of their contours, the isolation of the parts, and their fitting with 2D superquadrics are reported. The reconstruction of objects from their structural description is illustrated and improvements are suggested.

Bi-weekly 2-day schedule of high-dose folinic acid, 5-fluorouracil bolus and infusion in pretreated advanced epithelial ovarian cancer: a phase II study

Twenty patients with documented progression after two or three cisplatin-based regimens for advanced epithelial ovarian carcinoma were treated with high-dose folinic acid (200 mg/m2), 5-fluorouracil bolus (400 mg/m2) and continuous infusion (600 mg/m2) for two consecutive days every two weeks. One clinically complete and two partial responses were observed in 16 evaluable patients, with 5 remaining stable. Median survival was 9 months. Toxicity was mild. This combination achieved a 19% (95% confidence interval 4%-46%) response rate in heavily pretreated cisplatin-resistant patients.