Neoadjuvant chemotherapy (NACT) increases immune infiltration and programmed death-ligand 1 (PD-L1) expression in epithelial ovarian cancer (EOC)

Background

Lymphocytic infiltration at diagnosis is prognostic in EOC, however, the impact of NACT on tumour infiltrating lymphocytes (TILs) or PD-L1 expression remains poorly described.

Patients and methods

Patients with EOC and sequential samples (pre-NACT, post-NACT or relapse) were retrospectively identified. TILs were evaluated on whole sections; stromal TILs (sTILs) scored as percentage of stromal area with high sTILs defined as ≥50%; intra-epithelial TILs (ieTILs) scored semi-quantitatively (0-3) with high ieTILs ≥2. A smaller number were available for PD-L1 evaluation, cut-off for positivity was ≥5% staining.

Results

sTILs were detected in all tumours at diagnosis (range 2-90%, median 20%), with 22% (25/113) showing high sTILs. Among evaluable paired pre/post-NACT samples (N = 83), an overall increase in median sTILs from 20% to 30% was seen following NACT (P = 0.0005); individually the impact of NACT varied with sTILs increasing in 51% (42/83), decreasing in 25%, and stable in 24%. Post-NACT sTILs were predictive of platinum-free interval (PFI), patients with PFI ≥6 months had significantly higher post-NACT sTILs (sTILs 28% versus 18% for PFI <6 months, P = 0.026); pre-NACT sTILS were not predictive. At diagnosis, 23% showed high ieTILs, and following NACT 33% showed increasing ieTILs. Proportion of tumours with PD-L1-positive immune cells was 30% (15/50) pre-NACT and 53% (27/51) post-NACT (P = 0.026). Among paired tumours, 63% of PD-L1-negative tumours became positive after NACT, furthermore cisplatin induced PD-L1 expression in PD-L1-negative EOC cell lines. On multivariate analysis, high sTILs both pre- and post-NACT were independent prognostic factors for progression-free survival (PFS) (HR 0.49, P = 0.02 and HR 0.60, P = 0.05, respectively). No prognostic impact of ieTILs or PD-L1 expression was detected.

Conclusions

In EOC, sTILs levels are prognostic at diagnosis and remain prognostic after NACT. TILs and PD-L1 expression increase following NACT. Evaluation of immune parameters in the post-NACT tumour may help select patients for immunotherapy trials.

Fifth Ovarian Cancer Consensus Conference of the Gynecologic Cancer InterGroup (GCIG): clinical trial design for rare ovarian tumours

This manuscript reports the consensus statements on designing clinical trials in rare ovarian tumours reached at the fifth Ovarian Cancer Consensus Conference (OCCC) held in Tokyo, November 2015. Three important questions were identified concerning rare ovarian tumours (rare epithelial ovarian cancers (eOC), sex-cord stromal tumours (SCST) and germ cell tumours (GCT)): (i) What are the research and trial issues that are unique to rare ovarian tumours? There is a lack of randomised phase III data defining standards of care which makes it difficult to define control arms, but identifies unmet needs that merit investigation. Internationally agreed upon diagnostic criteria, expert pathological review and translational research are crucial. (ii) What should be investigated in rare eOC, GCT and SCST? Trials dedicated to each rare ovarian tumour should be encouraged. Nonetheless, where the question is relevant, rare eOC can be included in eOC trials but with rigorous stratification. Although there is emerging evidence suggesting that rare eOC have different molecular profiles, trials are needed to define new type-specific standards for each rare eOC (clear cell, low grade serous and mucinous). For GCTs, a priority is reducing toxicities from treatment while maintaining cure rates. Both a robust prognostic scoring system and more effective treatments for de novo poor prognosis and relapsed GCTs are needed. For SCSTs, validated prognostic markers as well as alternatives to the current standard of bleomycin/etoposide/cisplatin (BEP) should be identified. (iii) Are randomised trials feasible? Randomised controlled trials (RCT) should be feasible in any of the rare tumours through international collaboration. Ongoing trials have already demonstrated the feasibility of RCT in rare eOC and SCST. Mucinous OC may be considered for inclusion, stratified, into RCTs of non-gynaecological mucinous tumours, while RCTs in high risk or relapsed GCT may be carried out as a subset of male and/or paediatric germ cell studies.

Relationship between estrogen receptor, progesterone receptor, HER-2 and Ki67 expression and efficacy of aromatase inhibitors in advanced breast cancer

BACKGROUND

Surprisingly few data are published on the relevance of even commonly used biomarkers of response to aromatase inhibitors (AIs) in advanced breast cancer. Here, we aim to determine the effectiveness of AIs in that setting according to quantitative levels of estrogen receptor (ER), progesterone receptor (PgR) and Ki67 or human epithelial growth factor receptor-2 (HER-2) status.

PATIENTS AND METHODS

ER, PgR, HER-2 and Ki67 protein expressions were centrally assessed in 177 archival formalin-fixed paraffin-embedded primary or locally recurrent breast tumours from women who subsequently received AI treatment of advanced disease.

RESULTS

Among ER-positive patients (n = 146), higher PgR, but not ER, levels were associated with increased time to AI treatment failure (TTF). Higher Ki67 staining was associated with decreased TTF. ER-positive/HER-2-positive patients showed a non-significant trend for decreased TTF compared with ER-positive/HER-2-negative patients. PgR level, but not Ki67, remained a significant predictor of TTF in multivariate analysis of ER-positive patients.

CONCLUSIONS

Higher PgR and Ki67 levels are significantly associated with increased and decreased TTF, respectively, in ER-positive patients receiving AI treatment of advanced disease. The higher proliferation seen in PgR-negative tumours does not explain the poorer clinical responsiveness of this subgroup.

Abstract P3-14-03: Combining or Sequencing Targeted Therapies in ER+/HER2 Amplified Breast Cancer (BC): In Vitro and In Vivo Studies of Letrozole and Lapatinib in an ER+/HER2+ Aromatase-Transfected BC Model

Rationale: ER+/HER2+ BC may be resistant to endocrine therapies, but sensitive to HER2 inhibitors such as lapatinib. There is evidence that lapatinib may reactivate ERα expression1,2 raising the possibility that lapatinib may sensitize BC to subsequent endocrine therapy. Whether targeting the ER and HER2 in combination or in sequence in ER+/HER2+ BC may enhance anti-tumour effect is unknown. Aims: (1) To determine in ER+/HER2+ aromatase-expressing breast cancer models in vitro and in vivo.whether the combination of lapatinib with letrozole or tamoxifen is synergistic, and (2) to investigate whether using lapatinib and letrozole in sequence rather than in combination may provide a superior strategy.

Methods: ER+/HER2+ BT474 cells were stably transfected with aromatase (BTArom). Combination growth studies, immunoblots and gene expression assays were conducted in BTArom cells. BTArom xenograft studies were performed over 18 weeks under androstenedione support and mice randomized to daily treatment with vehicle, lapatinib, letrozole, or lapatinib and letrozole (L+L). In addition, mice in the lapatinib alone arm, were randomized at 6 weeks to continued lapatinib, vs. switch to letrozole, vs switch to L+L.

Results: Formal combination studies in aromatase-transfected BT474 (BTArom) cells demonstrated synergy between lapatinib and letrozole (combination index, CI=0.4, p&lt;10-5), but antagonism between lapatinib and 4-OH-tamoxifen (CI=1.34, p=0.05). In BTArom cells, lapatinib increased ESR1 2.8-fold (P&lt;0.0001) and ERα protein expression 2- fold. As expected, androstenedione upregulated both ER-controlled genes, PGR and GREB1, however lapatinib treatment increased PGR and GREB1 further, by 4.6- and 1.8—fold over androstenedione alone (p=0.0001 and p=0.045, respectively). In long-term BTArom xenografts the combination of lapatinib and letrozole was no more effective at controlling tumour growth than either treatment alone (Kruskall-Wallis comparing treatment arms, P&gt;0.05). However for the group of mice treated with lapatinib for 6 weeks followed by the combination of lapatinib and letrozole for 12 weeks, tumour volume increased only 2.2-fold, compared to 4.5-fold for those continuing on lapatinib, 5.7-fold for those switching to letrozole and 5.2-fold for those on lapatinib and letrozole from the start. Conclusion: We have demonstrated that HER2 targeted therapy enhanced responsiveness to aromatase inhibition in an ER+/HER2+ breast cancer model in vitro and in vivo. In contrast, the interaction between lapatinib and 4-OH-tamoxifen was antagonistic. Lapatinib increased ER expression and function, and the most effective tumour control was achieved with lapatinib alone followed by the combination of lapatinib and letrozole. Maximizing benefit from ER and HER2 targeted therapies in ER+/HER2+ BC may involve sequential rather than concurrent treatment to exploit lapatinib-induced ER reactivation. 1 Leary et al, Clin Canc Res 2010 2Xia et al, PNAS 2006

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-14-03.