Lacroix‐Triki, Magali

Assessment of tumor-infiltrating lymphocytes (TILs) in histopathologic specimens can provide important prognostic information in diverse solid tumor types, and may also be of value in predicting response to treatments. However, implementation as a routine clinical biomarker has not yet been achieved. As successful use of immune checkpoint inhibitors and other forms of immunotherapy become a clinical reality, the need for widely applicable, accessible, and reliable immunooncology biomarkers is clear. In part 1 of this review we briefly discuss the host immune response to tumors and different approaches to TIL assessment. We propose a standardized methodology to assess TILs in solid tumors on hematoxylin and eosin sections, in both primary and metastatic settings, based on the International Immuno-Oncology Biomarker Working Group guidelines for TIL assessment in invasive breast carcinoma. A review of the literature regarding the value of TIL assessment in different solid tumor types follows in part 2. The method we propose is reproducible, affordable, easily applied, and has demonstrated prognostic and predictive significance in invasive breast carcinoma. This standardized methodology may be used as a reference against which other methods are compared, and should be evaluated for clinical validity and utility. Standardization of TIL assessment will help to improve consistency and reproducibility in this field, enrich both the quality and quantity of comparable evidence, and help to thoroughly evaluate the utility of TILs assessment in this era of immunotherapy.

Assessment of the immune response to tumors is growing in importance as the prognostic implications of this response are increasingly recognized, and as immunotherapies are evaluated and implemented in different tumor types. However, many different approaches can be used to assess and describe the immune response, which limits efforts at implementation as a routine clinical biomarker. In part 1 of this review, we have proposed a standardized methodology to assess tumor-infiltrating lymphocytes (TILs) in solid tumors, based on the International Immuno-Oncology Biomarkers Working Group guidelines for invasive breast carcinoma. In part 2 of this review, we discuss the available evidence for the prognostic and predictive value of TILs in common solid tumors, including carcinomas of the lung, gastrointestinal tract, genitourinary system, gynecologic system, and head and neck, as well as primary brain tumors, mesothelioma and melanoma. The particularities and different emphases in TIL assessment in different tumor types are discussed. The standardized methodology we propose can be adapted to different tumor types and may be used as a standard against which other approaches can be compared. Standardization of TIL assessment will help clinicians, researchers and pathologists to conclusively evaluate the utility of this simple biomarker in the current era of immunotherapy.

Abstract Background: Ixabepilone, an epothilone B analog, has demonstrated single-agent activity in metastatic and neoadjuvant settings. The PACS08 trial aimed to compare adjuvant FEC100-Docetaxel regimen to FEC100-Ixabepilone in poor prognosis early breast cancer (BC) composed of patients presenting with triple-negative (TN) [i.e. estrogen receptor (ER)-/progesterone receptor (PR)-/HER2-] or ER+/PR-/HER2- tumor, which are subgroups significantly associated with worse prognosis. Patients and methods: Between 2007 and 2010, 762 patients with unilateral TNBC (n=592, 78%) or node-positive ER+/PR-/HER2- BC (n=170, 22%) were enrolled. Recruitment was interrupted due to BMS decision to stop ixabepilone development in adjuvant setting. Main inclusion criteria were: age<70 years, normal cardiac, hepatic, haematological and renal functions. Arm A: pts received 3 cycles of FEC100 (F and C, each at 500 mg/m2, E 100 mg/m2, every 3 weeks) followed by 3 cycles of Docetaxel (100 mg/m2 every 3 weeks); Arm B, Ixabepilone 40 mg/m2 replaced Docetaxel. Radiotherapy was mandatory after conservative surgery and endocrine therapy was given to ER+ pts. ER, PR and HER2 status were validated by a central pathology review on 754 cases and Immunohistochemical detection of Ki67, EGFR, cytokeratins (CK) 5/6 and 14, was performed on tissue microarray (TMA). Results: Main pts characteristics were well balanced between the 2 arms. As of September 2014, the median follow-up was 36 months. The safety profile indicates that Docetaxel is more often associated to significant haematological toxicities whereas both neurotoxicities and haematological toxicities are reported in Ixabepilone arm. Log-Rank tests indicate no difference between two arms in terms of both DFS and OS (HR=1.2, 95%CI (0.864-1.728), p=0.256 and HR=1.8, 95%CI (0.751-1.855), p=0.473, respectively). Pathological analysis of the PACS08 collection showed that TNBC displayed significantly higher proliferative activity as shown by mitotic count and Ki67 index (p<0.001). As compared to ER+/PR-/HER2- subgroup, TNBC showed distinct characteristics, and displayed a so-called basal-like phenotype in 80%. Further efficacy analyses are ongoing in order to study whether chemotherapy may have better prognosis according to pathological characteristics including tumor lymphocytic infiltrate. These additional data will be available for the SABCS2015 meeting. Conclusions: Our results indicate that Ixabepilone doesn't show higher efficiency compared to Docetaxel in adjuvant setting in poor prognosis early breast cancer. We have an unusual biological collection associated to our clinical data which will allow us to correlate efficacy data to breast cancer subgroups. Other several translational researches are still ongoing. Citation Format: Campone M, Lacroix-Triki M, Roca L, Spielmann M, Wildiers H, Cottu P, Kerbrat P, Levy C, Mayer F, Bachelot T, Wiston T, Eymard J-C, Uwer L, Machiels J-P, Verhoeven D, Jaubert D, Facchini T, Orfeuvre H, Canon J-L, Asselain B, Lemonnier J, Roché H. UCBG intergroup: 3-years efficacy results of the Unicancer-PACS08 trial including poor prognosis patients treated with docetaxel or ixabepilone in adjuvant setting. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-12-06.