Impact of sex on the efficacy and safety of panitumumab plus fluorouracil and folinic acid versus fluorouracil and folinic acid alone as maintenance therapy in RAS WT metastatic colorectal cancer (mCRC). Subgroup analysis of the PanaMa-study (AIO-KRK-0212)

BACKGROUND

Clinical trials in metastatic colorectal cancer (mCRC) are usually conducted irrespective of sex. Sex-associated differences relating to safety and efficacy in the treatment of mCRC, however, are gaining interest.

METHODS

PanaMa investigated the efficacy of panitumumab (Pmab) plus fluorouracil and folinic acid (FU/FA) versus FU/FA alone after induction therapy with six cycles of FU/FA and oxaliplatin plus Pmab in patients with RAS wild-type mCRC. In this post hoc analysis, the study population was stratified for sex. Evaluated efficacy endpoints during maintenance treatment were progression-free survival (PFS, primary endpoint of the trial), overall survival (OS) and objective response rate during maintenance therapy. Safety endpoints were rates of any grade and grade 3/4 adverse events during maintenance therapy.

RESULTS

In total, 165 male and 83 female patients were randomized and treated. Male and female patients showed numerically better objective response rates with Pmab, without reaching statistical significance. Male patients derived a significant benefit from the addition of Pmab to maintenance treatment with regard to PFS [hazard ratio (HR) 0.63; 95% confidence interval (CI) 0.45-0.88; P = 0.006] that was not observed in female patients (HR 0.85; 95% CI 0.53-1.35; P = 0.491). The better PFS for male patients treated with Pmab did not translate into improved OS (HR 0.85; 95% CI 0.55-1.30; P = 0.452). Female patients showed numerically improved OS when treated with Pmab. There was no difference in the total of grade ≥3 adverse events during maintenance regarding sex (P = 0.791). Female patients, however, had a higher rate of any grade nausea, diarrhea and stomatitis.

CONCLUSIONS

In the PanaMa trial, the addition of Pmab to maintenance treatment of RAS wild-type mCRC with FU/FA improved the outcome in terms of the primary endpoint (PFS) particularly in male patients. Female patients did not show the same benefit while experiencing higher rates of adverse events. Our results support the development of sex-specific protocols.

Prognostic and predictive value of CA 19-9 in locally advanced pancreatic cancer treated with multiagent induction chemotherapy: results from a prospective, multicenter phase II trial (NEOLAP-AIO-PAK-0113)

BACKGROUND

The prognostic and predictive value of carbohydrate antigen 19-9 (CA 19-9) in locally advanced pancreatic cancer (LAPC) has not yet been defined from prospective randomized controlled trials (RCTs).

PATIENTS AND METHODS

A total of 165 LAPC patients were treated within the NEOLAP RCT for 16 weeks with multiagent induction chemotherapy [ICT; either nab-paclitaxel/gemcitabine alone or nab-paclitaxel/gemcitabine followed by FOLFIRINOX (combination of fluorouracil, leucovorin, irinotecan, and oxaliplatin)] followed by surgical exploration of all patients without evidence of disease progression. CA 19-9 was determined at baseline and after ICT and correlated with overall survival (OS) and secondary R0 resection rate.

RESULTS

From the NEOLAP study population (N = 165) 133 patients (81%) were evaluable for CA 19-9 at baseline and 81/88 patients (92%) for post-ICT CA 19-9 response. Median OS (mOS) in the CA 19-9 cohort (n = 133) was 16.2 months [95% confidence interval (CI) 13.0-19.4] and R0 resection (n = 31; 23%) was associated with a significant survival benefit [40.8 months (95% CI 21.7-59.8)], while R1 resected patients (n = 14; 11%) had no survival benefit [14.0 (95% CI 11.7-16.3) months, hazard ratio (HR) 0.27; P = 0.001]. After ICT most patients showed a CA 19-9 response (median change from baseline: -82%; relative decrease ≥55%: 83%; absolute decrease to ≤50 U/ml: 43%). Robust CA 19-9 response (decrease to ≤50U/ml) was significantly associated with mOS [27.8 (95% CI 18.4-37.2) versus 16.5 (95% CI 11.7-21.2) months, HR 0.49; P = 0.013], whereas CA 19-9 baseline levels were not prognostic for OS. Multivariate analysis demonstrated that a robust CA 19-9 response was an independent predictive factor for R0 resection. Using a CA 19-9 decrease to ≤61 U/ml as optimal cut-off (by receiver operating characteristic analysis) yielded 72% sensitivity and 62% specificity for successful R0 resection, whereas CA 19-9 nonresponders (<20% decrease or increase) had no chance for successful R0 resection.

CONCLUSIONS

CA 19-9 response after multiagent ICT provides relevant prognostic and predictive information and is useful in selecting LAPC patients for explorative surgery.

CLINICAL TRIAL NUMBER

ClinicalTrials.govNCT02125136; https://clinicaltrials.gov/ct2/show/NCT02125136; EudraCT 2013-004796-12; https://www.clinicaltrialsregister.eu/ctr-search/trial/2013-004796-12/results.

Cilengitide combined with cetuximab and platinum-based chemotherapy as first-line treatment in advanced non-small-cell lung cancer (NSCLC) patients: results of an open-label, randomized, controlled phase II study (CERTO)

BACKGROUND

This multicentre, open-label, randomized, controlled phase II study evaluated cilengitide in combination with cetuximab and platinum-based chemotherapy, compared with cetuximab and chemotherapy alone, as first-line treatment of patients with advanced non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

Patients were randomized 1:1:1 to receive cetuximab plus platinum-based chemotherapy alone (control), or combined with cilengitide 2000 mg 1×/week i.v. (CIL-once) or 2×/week i.v. (CIL-twice). A protocol amendment limited enrolment to patients with epidermal growth factor receptor (EGFR) histoscore ≥200 and closed the CIL-twice arm for practical feasibility issues. Primary end point was progression-free survival (PFS; independent read); secondary end points included overall survival (OS), safety, and biomarker analyses. A comparison between the CIL-once and control arms is reported, both for the total cohorts, as well as for patients with EGFR histoscore ≥200.

RESULTS

There were 85 patients in the CIL-once group and 84 in the control group. The PFS (independent read) was 6.2 versus 5.0 months for CIL-once versus control [hazard ratio (HR) 0.72; P = 0.085]; for patients with EGFR histoscore ≥200, PFS was 6.8 versus 5.6 months, respectively (HR 0.57; P = 0.0446). Median OS was 13.6 for CIL-once versus 9.7 months for control (HR 0.81; P = 0.265). In patients with EGFR ≥200, OS was 13.2 versus 11.8 months, respectively (HR 0.95; P = 0.855). No major differences in adverse events between CIL-once and control were reported; nausea (59% versus 56%, respectively) and neutropenia (54% versus 46%, respectively) were the most frequent. There was no increased incidence of thromboembolic events or haemorrhage in cilengitide-treated patients. αvβ3 and αvβ5 expression was neither a predictive nor a prognostic indicator.

CONCLUSIONS

The addition of cilengitide to cetuximab/chemotherapy indicated potential clinical activity, with a trend for PFS difference in the independent-read analysis. However, the observed inconsistencies across end points suggest additional investigations are required to substantiate a potential role of other integrin inhibitors in NSCLC treatment.

CLINICAL TRIAL REGISTRATION ID NUMBER

NCT00842712.

Prognostic role of microRNA polymorphisms in advanced gastric cancer: a translational study of the Arbeitsgemeinschaft Internistische Onkologie (AIO)

BACKGROUND

To determine the prognostic role of selected microRNA (miRNA) polymorphisms in advanced gastric cancer (AGC).

PATIENTS AND METHODS

Six hundred and seventy-four AGC patients received 5-fluorouracil (F), leucovorin (L), oxaliplatin (O) or FL + cisplatin (P) or additional docetaxel (T) to FLO (FLOT) within four clinical trials. Polymorphisms of mir-26a1 (rs7372209), mir-27a (rs895819), mir-100 (rs1834306), mir-146a (rs2910164), mir-196-a2 (rs11614913), mir-219-1 (rs107822) and mir-423 (rs6505162) were genotyped. Variable selection for the final multivariate model (n = 487) was based on univariate and multivariate Cox-regression analyses with a cut-off P-value of ≤ 20%.

RESULTS

Genetic factors significantly associated with overall survival (OS) were rs7372209 (mir-26a1) variant genotypes (hazard ratio, HR 1.307 [95% confidence interval (CI) 1.031-1.656], P = 0.0272), rs895819 (mir-27a) variant genotypes (HR 1.304 [95% CI 1.031-1.650], P = 0.0270) and rs11614913 (mir-196a2) variant genotypes (HR 0.791 [95% CI 0.625-1.000], P = 0.0497). Clinical factors with significant impact on OS were Eastern Cooperative Oncology Group (ECOG) 2 performance status (HR 1.880 [95% CI 1.254-2.820], P = 0.0023), curative surgery of advanced disease (HR 0.235 [95% CI 0.123-0.449], P < 0.0001) and addition of docetaxel in locally AGC patients (HR 0.348 [95% CI 0.145-0.838], P = 0.0301). Combined analyses revealed an improved OS in patients without any unfavourable genotype of 18 months compared with 14, 12 and 10 months in patients with 1, 2 and 3 unfavourable genotypes, respectively (P = 0.0257).

CONCLUSIONS

These data suggest a significant impact of selected miRNA polymorphisms on prognosis in AGC.

Expression of dUTP nucleotidohydrolase (dUTPase) and thymidylate synthase (TS) in stage III colon cancer patients treated with either bolus 5-FU or infusional 5-FU in the adjuvant setting: Results of a translational study of the PETACC-2 trial

417

Background: Pts with stage III colon cancer have been treated with either infusional 5-FU or bolus 5- FU in the adjuvant setting (PETACC-2 trial). DUTPase and TS demonstrated potential as predictive markers for 5-FU efficacy in pts with advanced colorectal cancer. Here we aimed to explore whether TS or dUTPase protein levels may predict recurrence of disease for stage III colon pts treated with 5-FU.

Methods: Tumor (T) blocks of 324 pts were analyzed for protein expression of dUTPase and TS. For analysis monoclonal antibodies DUT415 and TS106 were used. T were evaluated by two investigators as follows. Only nuclear staining for both, TS and dUTPase, was analyzed. If tumor cells (TC) showed a nuclear dUTPase expression in >10% of cells, the sample was scored positive. Positive nuclear staining for >20% of TC, when using the TS antibody, determined a positive sample.

Results: Analysis for dUTPase was successful in 308 samples (95.1%, 308/324). 263 out of those 308 pts showed a positive dUTPase expression (85.3%). 297/324 samples (91.7%) could be evaluated for TS. In the TS group 62.3% (185/297) showed a positive expression for TS protein. In 281 cases analyses were successful for both TS and dUTPase. We observed a significant association between dUTPase and TS expression with a majotity of 71.4% (172/241) dUTPase positive T also being positive for TS as compared to 32.5% (13/40) of dUTPase negative T that showed positivity for TS protein expression (p< 0.0001). Of pts with dUTPase positive T 64.7% showed no recurrence of disease as compared to 44.7% of those with dUTPase negative T 5 years after completion of therapy (HR 0.61 [95% CI 0.36, 1.03], p=0.06). No associations between TS and DFS were observed. Both TS and dUTPase expression did not correlate with OS in this patient cohort.

Conclusions: High TS protein levels appeared to be significantly correlated with high protein levels of dUTPase in stage III colon cancer pts. Neither dUTPase nor TS protein levels appeared to be significantly associated with DFS or OS of stage III colon cancer pts that received adjuvant chemotherapy with 5-FU.

No significant financial relationships to disclose.

VEGF receptor 1 and heparanase expression as prognostic factors in cholangiocellular carcinoma

226

Background: Cholangiocellular carcinoma (CCC) remains to be a tumor with very few treatment choices and limited prognosis. In this study, we sought to determine the prognostic role of VEGF receptor 1 (VEGFR1), heparanase (HPSE) and EGF receptor (EGFR) gene expression in patients with resected CCC.

Methods: 47 formallin-fixed paraffin embedded FFPE tumor samples from patients with resected CCC were analyzed. FFPE tissues were dissected using laser-captured microdissection and analyzed for VEGFR1, HPSE and EGFR mRNA expression using a quantitative real-time RT-PCR method. Gene expression values (relative mRNA levels) are expressed as ratios between the target gene and internal reference genes (beta-actin, b2mg, rplp2, sdha).

Results: VEGFR1 and HPSE expression levels were significantly associated with overall survival (OS). Patients expressing low levels of VEGFR1 displayed a median OS of 23.2 months compared to 5.3 months in patients with high VEGFR1 expression (p=0.006, logrank test). Patients with low HPSE expression had a median OS of 19.8 months compared to 10.0 months in patients with high HPSE expression (p=0.02, logrank test). EGFR and PDGFRα expression were significantly associated with HPSE and VEGFR1 expression (p=0.03 and p<0.0001, respectively).

Conclusions: These results suggest that VEGFR1 and HPSE gene expression levels may play a role as prognostic factors in patients with CCC. Further studies are warranted to study these associations.

[Table: see text]

Preliminary results of a multicenter phase II study of imatinib and fluorourcail/leucovorin (FU/LV) in patients with unresectable or metastatic gallbladder or biliary tract cancer

e15622

Background: There are no standard chemotherapeutic regimens for incurable biliary adenocarcinomas. Monotherapies with gemcitabine or FU/LV achieve occasional responses and a median overall survival of about 6 months. By blocking PDGFR a decreased intrastromal pressure may increase therapy effects of chemotherapy. The combination of imatinib and FU/LV has been shown to be safe and feasible in a previous Phase I trial. This multicenter phase II trial was designed to investigate the disease control rate (DCR) of FU/LV and imatinib. Methods: Eligibility criteria included unresectable or metastatic measurable biliary tract cancer (BTC)/gallbladder cancer (GBC), performance status < 2, adequate organ function and no clinically significant cardiovascular disease. Enrolment of 44 chemonaive patients (pts.) was planned. Pts. received LV 200 mg/m2 followed by FU 2000 mg/m2 as a 24-hour infusion on days 1 and 2 combined with 600mg imatinib on days -4 to 4 (8 days). Cycles were repeated every 2 weeks up to 12 cycles. Radiological assessments were performed every 4 cycles. Results: 41 pts (19 GBC; 22 BTC) were enrolled in this phase II study since May 2007. Median age was 62 years (range 33–77), male/female=24/17, ECOG 0/1/2=13/23/5. 35 pts. showed metastatic disease at baseline. Treatment was well tolerated. Treatment related grade 3/4 toxicities included (number of pts): diarrhea (2), edema (1), neutropenia (2), nausea (2), transient SGPT elevation (4). The DCR of 26 pts. available for response assessment at time of analysis 1 was 58% (15 pts) (1 CR, 1 PR,13 SD of at least 4 cycles). 11 pts. showed progressive disease (PD) per RECIST criteria. 3 pts. had disease stabilization after 12 cycles and continue on treatment. We present these preliminary data as they represent a large patient number in this entity and response data are promising. Conclusions: This preliminary analysis suggests that the combination of FU/LV and imatinib can be safely administrated in pts. with GBC/BTC. Early evidence of antitumor activity was seen with some pts. achieving long term stabilization of the disease.

[Table: see text]

Pharmacogenetics of peripheral neuropathy in elderly patients (>65 years) with advanced gastric cancer receiving oxaliplatin-based chemotherapy within a randomized phase II study

e14515

Background: Peripheral neuropathy (PNP) is a dose-limiting side effect of oxaliplatin based chemotherapy. High grade PNP may compromise quality of life especially in elderly patients (pts). A randomized multicenter phase II study was conducted to compare fluorouracil, leucovorin, oxaliplatin with or without docetaxel (FLO vs. FLOT, respectively) in elderly pts with advanced gastric cancer (AGC). Our purpose was to identify pharmacogenetic markers as predictors of high grade PNP within this study. Methods: 143 pts were enrolled in this study. Pts. were numerically >65 years or numerically >59 years but classified biologically >65 years as defined by an Instrumental Activities of Daily Living score of <8. PNP was classified according to an oxaliplatin specific scale. Genotyping was performed using PCR-based RFLP or TaqMan®-based allelic discrimination. 20 polymorphisms in 13 genes being part of the metabolism of the applied drugs or DNA repair were analyzed. Statistical analyses were based on stepwise multivariate cox regression models and included genotypes and clinical parameters. Results: Median age was 71 years (range 60–83). Pts received in median 6 cycles of treatment (range 1–12). 130 pts were evaluable for PN at time of analyses. Of these, 68 received FLO and 62 received FLOT. Cumulative grade 3 PNP occurred in 49% of pts without a significant difference between FLO and FLOT receiving pts (44% and 53%, respectively, p=0.4). Genotypes of TS and MTHFR could be identified as independent risk factors for grade 3 PNP by multivariate analyses. Pts carrying a TS promoter genotype known to be associated with low TS expression (2R/2R, 2R/3RC, 3RC/3RC) were at higher risk for developing grade 3 PNP compared to pts without one of these genotypes (OR 3.0 [95%CI 1.27; 7.06], p=0.01). Pts carrying MTHFR1298AC or CC genotypes were also at higher risk for experiencing grade 3 PNP compared to pts with the wildtype MTHFR-1298AA genotype (OR 3.1 [95%CI 1.26; 7.60], p=0.01). In fact, 89% of pts that experienced grade 3 PNP were carriers of at least one of these risk genotypes. Conclusions: Polymorphisms of TS and MTHFR might be associated with grade 3 PNP in AGC pts receiving oxaliplatin based chemotherapy.

No significant financial relationships to disclose.

Thymidylate synthase polymorphisms and immunohistochemistry in non-small cell lung cancer

11101

Background: Recently, pemetrexed has been introduced into the treatment of non-small cell lung cancer (NSCLC). There's evidence that pemetrexed appears to be more efficient in non squamous NSCLC including adenocarcinoma (AC) and large cell carcinoma (LCC). TS represents a major target enzyme of pemetrexed. We evaluated the expression of TS among different histological types of NSCLC and its association with functional genetic polymorphisms of the TS gene. Methods: Archived tumor samples from 312 individuals with NSCLC were analyzed. Immunohistochemistry (IHC) was performed using a mouse monoclonal antibody to TS. TS stained sections were scored for cytoplasmic and nuclear localization. For each compartment, the tumor was evaluated for the estimated percentage of positive cells with the greatest intensity within the tumor. Intensity was scored on a scale of 0–4. A score of 3–4 was classified as high expression. Genotyping of TS-VNTR including the G/C SNP and TS1394del6 was performed by PCR based RFLP techniques. Genotypes supposed to be associated with low expression were grouped (group A: 2R/2R or 2R/3RC or 3RC/3RC + -6/-6) and compared to genotype groups associated with high expression (group B: 2R/3RG or 3RC/3RG or 3RG/3RG + -6/+6 or +6/+6). Results: IHC and polymorphisms could be performed successfully in 312 (100%) and 287 (92%), respectively. Distribution of histology was as follows: 50% AC, 42% squamous cell carcinoma (SCC), 3% LCC and 5% mixed or other histological subtypes. Group B genotypes were significantly more present in SCC than in AC (49% vs 23%, p=.002). Tumors with group B genotypes were more likely to display high nuclear staining intensity than group A tumors (30% vs. 17%, p=.077). A similar but not significant trend was seen for cytoplasmic staining intensity. There was no significant difference between histological subtypes of NSCLC with respect to TS protein expression. AC were more common than SCC to show a G1 differentiated tumors (8% vs 1%, p<.001). No difference between genotype groups were observed with respect to grading. Conclusions: TS polymorphisms are significantly associated with histology subtypes in NSCLC. These results represent a potential explanation for efficacy differences of pemetrexed in NSCLC and warrants further investigations.

[Table: see text]

Preliminary results of a multicenter phase II study of imatinib and fluorourcail/leucovorin (FU/LV) in patients with unresectable or metastatic gallbladder or biliary tract cancer

e15502

Background: There are no standard chemotherapeutic regimens for incurable biliary adenocarcinomas. Monotherapies with gemcitabine or FU/LV achieve occasional responses and a median overall survival of about 6 months. By blocking PDGFR a decreased intrastromal pressure may increase therapy effects of chemotherapy. The combination of imatinib and FU/LV has been shown to be safe and feasible in a previous Phase I trial. This multicenter phase II trial was designed to investigate the disease control rate (DCR) of FU/LV and imatinib. Methods: Eligibility criteria included unresectable or metastatic measurable biliary tract cancer (BTC)/gallbladder cancer (GBC), performance status < 2, adequate organ function and no clinically significant cardiovascular disease. Enrolment of 44 chemonaive patients (pts.) was planned. Pts. received LV 200 mg/m2 followed by FU 2000 mg/m2 as a 24-hour infusion on days 1 and 2 combined with 600mg imatinib on days -4 to 4 (8 days). Cycles were repeated every 2 weeks up to 12 cycles. Radiological assessments were performed every 4 cycles. Results: 41 pts (19 GBC; 22 BTC) were enrolled in this phase II study since May 2007. Median age was 62 years (range 33–77), male/female=24/17, ECOG 0/1/2=13/23/5. 35 pts. showed metastatic disease at baseline. Treatment was well tolerated. Treatment related grade 3/4 toxicities included (number of pts): diarrhea (2), edema (1), neutropenia (2), nausea (2), transient SGPT elevation (4). The DCR of 26 pts. available for response assessment at time of analysis 1 was 58% (15 pts) (1 CR, 1 PR,13 SD of at least 4 cycles). 11 pts. showed progressive disease (PD) per RECIST criteria. 3 pts. had disease stabilization after 12 cycles and continue on treatment. We present these preliminary data as they represent a large patient number in this entity and response data are promising. Conclusions: This preliminary analysis suggests that the combination of FU/LV and imatinib can be safely administrated in pts. with GBC/BTC. Early evidence of antitumor activity was seen with some pts. achieving long term stabilization of the disease.

[Table: see text]

Dose escalating study of 5-FU/folinic acid (FA)/oxaliplatin/irinotecan (FOLFOXIRI) and cetuximab in first-line therapy of patients with metastatic colorectal cancer

e15025

Background: Highly active chemotherapy schedules are necessary in several clinical situations, i.e. for conversional chemotherapy in order to resect liver metastases. Adding oxaliplatin or cetuximab to 5-FU / FA / irinotecan was shown to increase the efficacy of chemotherapy in patients with metastatic colorectal cancer (Falcone et al, JCO 2007, Van Cutsem et al, ASCO 2008). Methods: We performed a phase I study in patients (pts) with metastatic colorectal cancer, WHO PS 0–1 who had not been pretreated for metastatic disease. They received cetuximab (500 mg/m2, 2h), oxaliplatin (85 mg/m2, 2h), folinic acid (400 mg/m2, 2h), irinotecan (95, 125, or 165 mg/m2, 1h), 5-FU (3200 mg/m2, 46 h), each on day 1 in biweekly cycles. Dose was escalated if dose limiting toxicities (DLT) were absent in the first three pts per cohort, or if <2 DLTs in six pts. Non-evaluable pts were replaced. Pts were not selected for EGFR IHC or KRAS status. Results: Twenty-one pts were enrolled into the study between Jan 2007 and June 2008, six evaluable pts per each cohort. Two pts who had adverse events deemed unrelated to study during the first cycle (morphine overdosing, mechanical ileus) were replaced, one patient (port dysfunction during first dose) was excluded from analysis. Patient characteristics were as follows: median age 59 (33–72) years, 16 pts WHO PS 0, 15 pts male, 10 pts rectal cancer primary, 3 pts previous adjuvant chemotherapy. In the first two cohorts, 95 and 125 mg/m2 irinotecan, one DLT occurred per dose level (neutropenia gr. 4 and diarrhea gr. 3). In the 165 mg/m2 cohort, 2 DLTs were observed (neutropenia grade 4). Most common grade ≥ 3 toxicities were neutropenia (40%), diarrhea (25%), skin toxicities (15%), thrombopenia (10%) and infections (15%). One patient had a confirmed complete response, 14 pts had confirmed partial response (ORR 75%, 95% CI: 51–91%), 5 pts stable disease. Median progression free survival has not yet been reached. Conclusions: With the combination of FOLFOXIRI/cetuximab, the recommended dose of irinotecan is 125 mg/m2 for further investigation in clinical trials in patients with good performance status. The observed response rate of 75% is very promising.

[Table: see text]

Pharmacogenetic analyses of hematotoxicity in advanced gastric cancer patients receiving biweekly fluorouracil, leucovorin, oxaliplatin and docetaxel (FLOT): a translational study of the Arbeitsgemeinschaft Internistische Onkologie (AIO)

BACKGROUND

Docetaxel-based chemotherapy regimens have demonstrated activity in advanced gastric cancer (AGC). However, a high rate of grade 3/4 hematotoxicity was reported with these regimens. Our purpose was to identify pharmacogenetic markers with potential to detect patients with increased risk to encounter severe hematotoxicity following treatment with 5-fluorouracil, leucovorin, oxaliplatin and docetaxel (FLOT).

PATIENTS AND METHODS

Polymorphisms of genes involved in DNA repair, drug transport and metabolism were determined in 50 AGC patients receiving FLOT within a phase II trial. DNA was extracted from peripheral blood. Genotyping was carried out using PCR-based techniques.

RESULTS

Patients possessing TS-group A genotypes (2R/2R, 2R/3RC, 3RC/3RC) were at increased risk for grade 3/4 hematotoxicity compared with patients harboring a TS-group B genotype (2R/3RG, 3RC/3RG, 3RG/3RG). In all, 59% (20 of 34) of patients with TS-group A genotypes developed grade 3/4 hematotoxicity compared with 25% (4 of 16) of those having TS-group B genotypes (P=0.035). Grade 3/4 neutropenia occurred in 53% (18 of 34) of TS-group A patients compared with 19% (3 of 16) in TS-group B patients (P=0.032). Multivariate analyses identified TS-group A genotypes as significant predictors of grade 3/4 overall hematotoxicity {odds ratio (OR) 4.62 [95% confidence interval (CI) 1.22; 17.44], P=0.024} and neutropenia [OR 5.74 (95% CI 1.03; 32.08), P=0.047].

CONCLUSION

TS-promoter polymorphisms may be associated with hematotoxicity in AGC patients receiving FLOT.

Preliminary pharmacogenetic evaluation of toxicity data in the prospective multicentre EORTC trial 40015 in metastatic colorectal cancer (CRC)

3072

Background: EORTC phase III study 40015 was initiated in 2003 to compare capecitabine (C) + irinotecan (CPT-11) vs 5FU/LV/irinotecan ± celecoxib in 1st line treatment of mCRC. The study was suspended after enrollment of 85 pts due to 8 fatal events not related to disease progression, 4 of which included thrombo-embolic events. Purpose: To test whether genetic polymorphisms involved in metabolism of the drugs are related to the increased toxicity observed in the study. Methods: 71 pts signed informed consent for genetic analyses and material was available for 58 pts. DNA was extracted from normal colonic mucosa or peripheral leukocytes. Polymorphisms were determined using PCR-based RFLP and direct sequencing. Genotypes known to be associated with increased toxicity (diarrhea, mucositis, leucopenia) were classified as unfavorable. Results: Unfavorable genotypes were distributed equally between C+CPT-11 and LV/5FU+CPT-11 arms. Baseline characteristics and treatment duration were similar in the pts with or without unfavorable genotypes. Unfavorable genotypes of thymidylate synthase (TS-5; TS-3) and UDP-glucuronosyltransferase 1A1 (UGT1A1) were associated with increased grade 3/4 toxicity. 18/35 (51%) pts with unfavorable UGT1A1 genotype experienced toxicity grade 3/4 compared to 3/23 (13%) pts with favorable genotype. 16/36 pts (44%) with unfavorable TS-5 genotype showed toxicity grade 3/4 compared to 5/22 (23%) pts with favorable genotype. Toxicity grade 3/4 was observed in 18/41 (44%) pts with unfavorable TS-3 genotype and 3/17 (18%) pts with favorable genotype. Increasing grade 3/4 toxicity rates were observed in the pts expressing 0/1 (2/16 [13%]), 2 (7/24 [29%]) or 3 (12/16 [75%]) unfavorable genotype(s) (p=0.0001). Among the 4 pts who died of a thrombo-embolic event, only one has been analysed at this stage and showed a Factor (V) Leiden mutation linked to 10-fold increased risk for thrombo-embolic events. Analyses are ongoing and complete data will be available for presentation. Conclusion: Our data suggest an association between polymorphisms of TS and UGT1A1 and toxicity. No differences of pharmacogenetic patterns were observed that could explain the increased rate of fatal events in the C/CPT-11 arm.

[Table: see text]

Polymorphisms of glutathione S-transferases (GST) and thymidylate synthase (TS)--novel predictors for response and survival in gastric cancer patients

To evaluate the predictive value of a panel of gene polymorphisms involved in metabolism of 5-FU and cisplatin on clinical outcome in advanced gastric cancer patients. A total of 52 patients were enrolled in this study. DNA was extracted from paraffin-embedded tumour specimen. Genotypes were determined using PCR-RFLP. Median survival time was 6.0 months (95% CI 3.9;8.1). Overall response rate was 26%. Patients possessing the glutathione S-transferase P1-105 Valine/Valine (GSTP1-105VV) genotype showed a response rate of 67% compared to 21% in patients harbouring at least one GSTP1-105 Isoleucine (GSTP1-105I) allele (P=0.038). GSTP1-105VV patients demonstrated a significant superior median survival time of 15.0 months (95% CI 7.8;22.0) compared to 6.0 months (95% CI 5.1;7.0) in patients with at least one GSTP1-105I allele (P=0.037). Patients possessing a favourable thymidylate synthase (TS) genotype (2R/2R, 2R/3RC, 3RC/3RC) experienced a superior survival time of 10.2 months (95% CI 5.1;15.3) compared to 6.0 months (95% CI 5.0;7.0) in patients with unfavourable TS genotypes (P=0.099). Patients harbouring the GSTP1-105II genotype and one of the unfavourable TS genotypes showed an inferior median survival time of 6.0 months (95% CI 3.9;8.1) compared to 11 months (95% CI 6,23;15,77) in patients with either GSTP1-105VV or a favourable TS genotype (P=0.044). Testing for TS and GSTP1 polymorphisms may allow identification of gastric cancer patients who will benefit from 5-FU/cisplatin chemotherapy, sparing others the side effects of this chemotherapy.