Atanas Ignatov

GANNET53 Part II: A European Phase I/II Trial of the HSP90 Inhibitor Ganetespib in High-Grade Platinum-Resistant Ovarian Cancer—A Study of the GANNET53 Consortium

Abstract Purpose: Mutant p53 stabilized by heat shock protein 90 (HSP90) is a novel target in oncology. The open-label, randomized phase II GANNET53 trial is the first to evaluate the HSP90 inhibitor ganetespib (G) with paclitaxel (P) in platinum-resistant epithelial ovarian cancer (EUDRACT 2013-003868-31; EU FP7 #602602). Patients and Methods: Patients were randomized 2:1 to receive G + P or P alone until progression. Primary endpoints were progression-free survival (PFS) and PFS rate at 6 months. Exploratory endpoints were biomarkers based on p53 and HSP90. Results: A total of 133 patients were enrolled. The median PFS was 3.5 (G + P) and 5.3 months (P) (HR = 1.3; 95% confidence interval, 0.897–1.895; P = 0.16), and PFS rates at 6 months were 22% (G + P) and 33% (P). No significant differences were found in overall survival, objective response rate, and post-progression PFS between arms. The most frequent adverse events were diarrhea (79% vs. 26%), anemia (46% vs. 51%), nausea (41% vs. 40%), and peripheral neuropathy (36% vs. 47%). Serious adverse events were more common in G + P (39.5% vs. 23.3%). Gastrointestinal perforation was a new safety finding. Despite a high TP53 mutation frequency, HSP90–p53 complexes were detected in only 39.6% of the cases and were also detected stably during treatment. In vitro, no synergistic effects of G + P were observed, and mutant p53 depletion did not sensitize ovarian cancer cells to treatment. Conclusions: Although no major safety findings were observed, G + P did not lead to survival benefit. Our companion diagnostic program confirmed that G + P do not favorably cooperate in killing ovarian cancer cells.

Comparison of survival of patients with endometrial cancer undergoing sentinel node biopsy alone or systematic lymphadenectomy

Recently, sentinel lymph node mapping was introduced in the surgical staging of endometrial cancer as alternative to systematic lymphadenectomy. However, the survival impact of sentinel node mapping is not well characterized yet. We performed retrospective study of 104 patients with endometrial cancer treated with sentinel lymph node alone (n = 52) or with pelvic and para-aortic lymphadenectomy (n = 52). For sentinel node mapping, indocyanine green was used. The outcome measure was disease-free survival. Median follow-up was 42 months. Fifty-two patients staged by sentinel lymph node mapping were matched in 1:1 ratio with 52 patients staged by lymphadenectomy using patient age, histological type, tumor stage, tumor grade and lymph and vascular space invasion as matching criteria. The median number of removed lymph node was 3 (range 1-6) and 36 (13-63) in the sentinel and lymphadenectomy group, respectively. The rate of lymph node metastases was not significantly higher in the sentinel group (19.2%) in comparison with the lymphadenectomy group (14.3%). The overall detection rate of sentinel lymph nodes was 100% with a bilateral mapping of 98.1%. Most of the 152 lymph nodes identified and removed were localized in upper paracervical pathway (n = 143, 94.1%). During the follow-up period, overall 21 (20.2%) events were observed, 8 (15.4%) in the sentinel group and 13 (25.0%) in the lymphadenectomy group. The estimated disease-free survival was 84.6% and 75.0% for patients in the sentinel and lymphadenectomy groups, respectively. The survival curves demonstrated similar disease-free survival in two groups (p = 0.774). Sentinel lymph node mapping did not compromise the outcome of patients with endometrial cancer.

Systematic lymphadenectomy in early stage endometrial cancer

The positive effect of systematic lymphadenectomy on survival of patients with endometrial cancer is a topic of ongoing debate. We aimed to investigate whether systemic lymphadenectomy is beneficial for patients with early endometrial cancer. For this purpose, we analyzed a population-based registry with of 2392 women with endometrioid endometrial cancer, stage I and II at intermediate and high risk of recurrence. The primary outcome measure was overall survival. After exclusions, 868 women were eligible for analysis. Of those, 511 and 357 were categorized as intermediate (pT1A G3 and pT1B G1-2) and high risk (pT1B G3 and pT2 G1-3) early stage endometrial cancer, respectively. Lymphadenectomy was performed in 527 (60.7%) of the cases. Patients in the lymphadenectomy group were significantly younger, presented with more tumors of intermediate or undifferentiated grade and exhibited significantly lower co-morbidity rates and Eastern Cooperative of Oncology Group (ECOG) performance status. Median follow-up was 6.7 years. Recurrence-free survival was not improved by lymphadenectomy in the intermediate and high-risk group of patients. During the follow-up period, 111 (12.8%) women had disease recurrence and 302 (34.8%) died. Systematic lymphadenectomy was associated with significant improvement of overall survival in the pT1A G3 and pT1B G3 patient subgroups. Notably, adjustment for patient age and ECOG status abolished the improvement of overall survival by systematic lymphadenectomy in all groups. Thus, lymphadenectomy did not improve recurrence-free survival in the intermediate risk or the high-risk group of patients CONCLUSIONS: Systematic pelvic and para-aortic lymphadenectomy did not improve the survival of patients with early stage I and II endometrioid endometrial cancer at intermediate and high risk of recurrence.

Contralateral lymph node metastases in patients with vulvar cancer and unilateral sentinel lymph node metastases

AbstractIntroductionThe risk of contralateral lymph node metastases following unilateral sentinel lymph node (SLN) metastases in patients with vulvar cancer(s) remains to be systematically assessed.Material and methodsWe performed a multicenter, retrospective registry‐based study of 476 patients with vulvar cancer. The primary outcome measure was the rate of contralateral non‐SLN metastases in the case of positive unilateral SLN.ResultsOut of 476 patients with primary vulvar cancer, 202 received SLN biopsy: 58 unilateral and 144 bilateral. Out of 66 patients with unilateral metastatic SLN, 62 (93.9%) received contralateral lymphadenectomy—18 after unilateral and 44 after bilateral SLN biopsy. In the study group, 132 SLN were assessed with a median number of 2 (range 1–4) per patient and 76 of these were positive. Lymph node‐positivity was associated with advanced tumor stage, as well as lymph and vascular space invasion. In the group of patients with bilateral inguino‐femoral lymphadenectomy, 1004 lymph nodes were resected with a median number of 15 (range 10–29) per patient. After full dissection of the inguino‐femoral lymph nodes, no contralateral non‐SLN metastases were found.ConclusionsThe risk of contralateral non‐SLN metastases in patients with unilateral SLN metastases was low. Therefore, the impact of contralateral lymphadenectomy on patient survival should be investigated in further studies.

Minimal-invasive or open approach for surgery of early cervical cancer: the treatment center matters

The aim of the study was to compare recurrence-free survival (RFS) and overall survival (OS) of patients with early stage cervical cancer in dependence of surgical approach and treatment center. A population-based cohort study including women with early stage IA1-IIB2 cervical cancer treated by radical hysterectomy between January 2010 and December 2015 was performed. The median follow-up time was 5.6 years. After exclusions, 413 patients were eligible for analysis: 111 (26.9%) underwent minimal-invasive surgery (MIS) and 302 (73.1%) open surgery. Both treatment groups were well balanced regarding the clinical and pathological characteristics. The mean age of the patients was 51.0 years. MIS was associated with improved RFS and OS compared with the open surgery. The 5-year RFS rates were 89.2% in the MIS group and 73.4% in the open surgery group (p = 0.004). The 5-year OS rates were 93.7% in the MIS group and 81.8% in the open surgery group (p = 0.016). After adjustment for other prognostic covariates, the MIS was further associated with improved RFS (HR = 0.45, 95% CI 0.24-0.86; p = 0.015) but not with OS. Nevertheless, after adjustment for treatment center, the surgical approach was not associated with significant difference in RFS (HR = 0.61, 95% CI 0.31-1.19; p = 0.143). Overall survival of patients treated in university cancer centers was significantly increased compared to patients treated in non-university cancer centers. The treatment center remains a strong prognostic factor regarding RFS (HR = 0.49, 95% CI 0.28-0.83; p = 0.009) and OS (HR = 0.50, 95% CI 0.26-0.94; p = 0.031). The treatment center but not the surgical approach was associated with the survival of patients treated with radical hysterectomy for early stage cervical cancer.