Efficacy of adjuvant capecitabine in residual triple negative breast cancer: a multicenter observational Turkish Oncology Group (TOG) study.

BACKGROUND: Triple negative breast cancer (TNBC) is characterized by high rates of recurrence, especially in patients with residual disease after neoadjuvant chemotherapy (NAC). Capecitabine is being used as standard adjuvant treatment in residual TNBC. We aimed to investigate the real-life data regarding the efficacy of capecitabine in residual TNBC. DESIGN AND METHODS: In this retrospective multicenter study, TNBC patients with residual disease were evaluated. Patients, who received standard anthracycline and taxane-based NAC and adjuvant capecitabine were eligible. Overall survival (OS), disease free survival (DFS) and toxicity were analyzed. RESULTS: 170 TNBC patients with residual disease were included. Of these, 62.9% were premenopausal. At the time of analysis, the recurrence rate was 30% and death rate was 18%. The 3-year DFS and OS were 66% and 74%, respectively. In patients treated with adjuvant capecitabine, residual node positive disease stood out as an independent predictor of DFS (p = 0.024) and OS (p = 0.032). Undergoing mastectomy and the presence of T2 residual tumor was independent predictors of DFS (p = 0.016) and OS (p = 0.006), respectively. CONCLUSION: The efficacy of capecitabine was found lower compared to previous studies. Selected patients may have further benefit from addition of capecitabine. The toxicity associated with capecitabine was found lower than anticipated.

Comparing the efficacy of regorafenib and 5-fluorouracil-based rechallenge chemotherapy in the third-line treatment of metastatic colorectal cancer.

BACKGROUND: The optimal treatment for metastatic colorectal cancer (mCRC) after the second line is still controversial. Regorafenib has been the standard of care in this setting as it improved overall survival (OS) compared to placebo. In real-world practice chemotherapy rechallenge is also a preferred option even though supporting evidence is not enough. We aim to compare the efficacy of regorafenib and 5-fluorouracil-based (5-FU) rechallenge treatment in the third line setting of mCRC. METHODS: In this retrospective multi-institutional trial, mCRC patients from 21 oncology centers who progressed after 2 lines of chemotherapy were analyzed. Patients who were treated with regorafenib or rechallenge therapy in the third-line setting were eligible. Rechallenge chemotherapy was identified as the re-use of the 5-FU based regimen which was administered in one of the previous treatment lines. OS, disease control rate (DCR), progression free survival (PFS) and toxicity were analyzed. RESULTS: Three hundred ninety-four mCRC patients were included in the study. 128 (32.5%) were in the rechallenge, and 266 (67.5%) were in the regorafenib group. Median PFS was 5.82 months in rechallenge and 4 months in regorafenib arms (hazard ratio:1.45,95% CI, p = 0.167). DCR was higher in the rechallenge group than regorafenib (77% vs 49.5%, respectively, p = < 0.001). Median OS after the third-line treatment was 11.99 (95% CI, 9.49-14.49) and 8.08 months (95% CI, 6.88-9.29) for rechallenge and regorafenib groups, respectively (hazard ratio:1.51, 95% CI, p < 0.001). More adverse effects and discontinuation were seen with regorafenib treatment. CONCLUSION: Our study revealed that higher disease control and OS rates were achieved with rechallenge treatment compared to regorafenib, especially in patients who achieved disease control in one of the first two lines of therapy.

The effect of concomitant proton pump inhibitor use on survival outcomes of Nivolumab-treated renal cell carcinoma patients: a multicenter study.

AIM: We aimed to evaluate the effect of concomitant proton pump inhibitors (PPI) use with nivolumab on survival outcomes in metastatic renal cell carcinoma (mRCC) in second-line setting. METHODS: The study was designed as a multicenter and retrospective involving patients with metastatic renal cell carcinoma receiving second-line nivolumab therapy. One hundred and nine patients with mRCC were divided into two groups based on whether they use PPI concomitantly with nivolumab: concomitant PPI users and non-users. Overall survival (OS) and progression-free survival (PFS) were compared between the groups with and without concurrent PPIs. RESULTS: Of 109 patients in our study, 59 were not using PPI concomitantly with nivolumab and 50 were using PPI concomitantly. The median PFS was 6.37 (5.2-7.5) months in the concomitant PPI group and 9.7 (4.5-15) months in the non-users (p = 0.03). The median OS was 14.6 (7.1-22.1) months in patients on PPI concurrently with nivolumab and 29.9 (17.1-42.7) months in the non-users (p = 0.01). Accordingly, PPI use for PFS (Non-use vs. Use = HR: 0.44, 95%Cl 0.28-0.96, p = 0.014) and PPI use for OS (Non-use vs. Use = HR: 0.68, 95%Cl 0.22-0.88, p = 0.01) were found to be as independent risk factors. CONCLUSIONS: Concomitant use of PPIs is associated with worse survival outcomes in patients with mRCC treated with nivolumab. Clinicians should carefully consider the concomitant use of PPIs in such patients.

The effect of concomitant use of proton pump inhibitors with CDK 4/6 inhibitors on survival in metastatic breast cancer.

AIM: To evaluate the difference of progression free survival between the patients using concomitant proton pump inhibitors and non-users in the patients using CDK 4/6 inhibitors with HR + and HER2 negative mBC. METHODS: We included 86 patients with HR + and HER 2 negative mBC treated with CDK 4/6 inhibitors in this study. Patients were divided into two categories according to their status of PPI use. The primary end points was progression free survival (PFS). We compared PPI users and non-users. RESULTS: Forty-five (52.3%) patients used a PPI concomitantly with a CDK 4/6 inhibitor, and 41 (47.7%) did not. The median duration of follow-up was 10.68 (1.94-27.56) months. Of the patients, 50 (58.1%) palbociclib and 36 (41.9%) received ribociclib. The median progression free survival (mPFS) was 10.9 months (95% CI: 7.5-14.27) in the group with concomitant PPI use with a CDK 4/6 inhibitor, whereas the median progression free survival could not be reached in the group without concomitant PPI use (p = 0.04). In addition, concomitant PPI use with palbociclib was associated with a shorter PFS; there was no significant difference between the concomitant PPI users and non-users in terms of PFS in the patients using ribociclib. CONCLUSION: Palbociclib and ribociclib are weak base drugs so their bioavailability is pH-dependent. PPIs can affect their solubility and their concentration in the plasma. Therefore, we must avoid concomitant use of PPIs and CDK 4/6 inhibitors. If we need to use concomitant PPI and CDK 4/6 inhibitors, we should prefer ribociclib than palbociclib.

Clinical outcomes of concomitant use of proton pump inhibitors and regorafenib in patients with metastatic colorectal cancer: a multicenter study.

AIM: To compare survival outcomes, response rates, and adverse events (AEs) in proton pump inhibitor (PPI) user and non-user patients with metastatic colorectal cancer (mCRC) treated with regorafenib. METHODS: We included 272 patients with mCRC treated with regorafenib in this study. Patients were divided into two categories according to their status of PPI use. The primary endpoint was overall survival (OS). The secondary endpoints were time to treatment failure (TTF), response rates, and safety. To exclude immortal time bias in survival analyses, we compared PPI non-user patients and all patients. RESULTS: There were 141 and 131 patients in the PPI non-user and user groups. Baseline characteristics were similar in each group. Pantoprazole was the most used PPI. At the median 35.2 (95% confidence interval (CI): 32.6-37.9) months follow-up, the median OS was similar in PPI non-user and all patients (6.9 months (95% CI: 5.3-8.5) and 7.7 months (95% CI:6.6-8.8), p = 0.913). TTF was also similar in PPI non-user and all patients (3.3 months (95% CI: 2.7-3.9) and 3.5 months (95% CI: 3.0-4.0), p = 0.661). In multivariable analysis, no statistically significant difference was observed between PPI user and non-user groups in OS and TTF (hazard ratio (HR), 0.99; 95% CI, 0.77-1.28; p = 0.963 for OS; HR, 0.93; 0.77-1.20, p = 0.598 for TTF). The objective response rates (ORR) were similar in the PPI non-user and user groups (19.8% and 16.8%, p = 0.455). The rates of any grade AEs were also similar in each group. CONCLUSION: This study found no worse outcome in the combined use of PPI and regorafenib among patients with mCRC.

Is pancreatic giant cell tumor resistant to standard chemotherapy?

Pancreatic giant cell tumors (PGCTs), undifferentiated pancreatic carcinoma are rare tumors of the pancreas. PGCTs consist of osteoclastic, pleomorphic and mixed variants. PGCT is usually diagnosed at an advanced stage. PGCT has a worse prognosis than pancreatic ductal adenocarcinoma. Although surgery can be curative, there is no standard treatment approach for advanced PGCT. We present a case of PGCT that is resistant to standard therapy and progresses in a short time.

First-line treatment of patients with HER2-positive metastatic gastric and gastroesophageal junction cancer.

Fluoropyrimidine+cisplatin/oxaliplatin+trastuzumab therapy is recommended for the first-line treatment of HER2-positive metastatic gastric adenocarcinoma. However, there is no comprehensive study on which platinum-based treatment should be preferred. This study aimed to compare the treatment response and survival characteristics of patients with HER2-positive metastatic gastric or gastroesophageal junction (GEJ) cancer who received fluorouracil, oxaliplatin, and leucovorin (mFOLFOX)+trastuzumab or cisplatin and fluorouracil (CF)+trastuzumab as first-line therapy. It was a multicenter, retrospective study of the Turkish Oncology Group, which included 243 patients from 21 oncology centers. There were 113 patients in the mFOLFOX+trastuzumab arm and 130 patients in the CF+trastuzumab arm. The median age was 62 years in the mFOLFOX+trastuzumab arm and 61 years in the CF+trastuzumab arm (P = 0.495). 81.4% of patients in the mFOLFOX+trastuzumab arm and 83.1% in the CF+trastuzumab arm had gastric tumor localization (P = 0.735). The median progression-free survival (PFS) was significantly higher in the mFOLFOX+trastuzumab arm (9.4 months vs. 7.3 months, P = 0.024). The median overall survival (OS) was similar in both groups (18.4 months vs. 15.1 months, P = 0.640). Maintenance trastuzumab was continued after chemotherapy in 101 patients. In this subgroup, the median OS was 23.3 months and the median PFS was 13.3 months. In conclusion, mFOLFOX+trastuzumab is similar to CF+trastuzumab in terms of the median OS, but it is more effective in terms of the median PFS in the first-line treatment of HER2-positive metastatic gastric and GEJ cancer. The choice of treatment should be made by considering the prominent toxicity findings of the chemotherapy regimens.