Immunoglobulin light chain transcript detection by ultrasensitive RNA in situ hybridization for B-cell lymphoma diagnosis.

Evaluation of B-cell clonality can be challenging in the interpretation of lymphoid infiltrates on tissue sections. Clonality testing based on IG gene rearrangements analysis by PCR (IG-PCR) is the gold standard. Alternatively, B-cell clonality can be assessed by the recognition of immunoglobulin light chain (IgLC) restriction, by immunohistochemistry (IHC), chromogenic in situ hybridization (ISH) or flow cytometry (FC). IG-PCR requires molecular facilities, and FC requires cell suspensions, both not widely available in routine pathology units. This study evaluates the performance of B-cell clonality detection by IgLC-RNAscope® (RNAsc) in a group of 216 formalin-fixed, paraffin-embedded samples including 185 non-Hodgkin B-cell lymphomas, 11 Hodgkin lymphomas (HL) and 20 reactive samples. IgLC-RNAsc, performed in parallel with FC in 53 cases, demonstrated better performances (93% vs 83%), particularly in diffuse large B-cell lymphoma (98% vs 71%) and follicular lymphoma (93% vs 83%) diagnosis. IgLC-RNAsc was also superior to IHC and ISH especially in samples with limited tumor cell content, where IG-PCR was not informative. Performed for the first time on mediastinal lymphomas, IgLC-RNAsc identified monotypic IgLC transcripts in 69% of primary mediastinal large B-cell lymphoma (PMBCL) and 67% of mediastinal gray zone lymphomas (MGZL). IGK/L double-negative cells were detected in 1 PMBCL, 2 MGZL, and all classical HL, while monotypic IgLC expression appeared to be a hallmark in nodular lymphocyte-predominant HL. IgLC-RNAsc demonstrates to be a powerful tool in B-cell lymphoma diagnosis, above all in challenging cases with limited tumor cell content, ensuring in situ investigations on mechanisms of Ig regulation across lymphoma entities.

Unresectable stage III non-small cell lung cancer: could durvalumab be safe and effective in real-life clinical scenarios? Results of a single-center experience.

Introduction: The standard of care for patients with unresectable stage III non-small cell lung cancer (NSCLC) is chemoradiotherapy (CRT) followed by consolidation durvalumab as shown in the PACIFIC trial. The purpose of this study is to evaluate clinical outcomes and toxicities regarding the use of durvalumab in a real clinical scenario. Methods: A single-center retrospective study was conducted on patients with a diagnosis of unresectable stage III NSCLC who underwent radical CRT followed or not by durvalumab. Tumor response after CRT, pattern of relapse, overall survival (OS) and progression-free survival (PFS), and toxicity profile were investigated. Results: Eighty-five patients met the inclusion criteria. The median age was 67 years (range 45-82 years). Fifty-two patients (61.2%) started sequential therapy with durvalumab. The main reason for excluding patients from the durvalumab treatment was the expression of PD-L1 < 1%. Only two patients presented a grade 4 or 5 pneumonitis. A median follow-up (FU) of 20 months has been reached. Forty-five patients (52.9%) had disease progression, and 21 (24.7%) had a distant progression. The addition of maintenance immunotherapy confirmed a clinical benefit in terms of OS and PFS. Two-year OS and PFS were respectively 69.4% and 54.4% in the durvalumab group and 47.9% and 24.2% in the no-durvalumab group (p = 0.015, p = 0.007). Conclusion: In this real-world study, patients treated with CRT plus durvalumab showed clinical outcomes and toxicities similar to the PACIFIC results. Maintenance immunotherapy after CRT has been shown to be safe and has increased the survival of patients in clinical practice.

Gastroblastoma in Adulthood-A Rarity among Rare Cancers-A Case Report and Review of the Literature.

Gastroblastoma (GB) is a rare gastric epithelial-mesenchymal neoplasm, first described by Miettinen et al. So far, all reported cases described the tumor in children or young adults, and similarities with other childhood blastomas have been postulated. We report a case of GB in a 43-year-old patient with long follow up and no recurrence up to 100 months after surgery. So far, this is the second case of GB occurring in the adult age >40-year-old. Hence, GB should be considered in the differential diagnosis of microscopically comparable conditions in adults carrying a worse prognosis and different clinical approach.

Protein drug target activation homogeneity in the face of intra-tumor heterogeneity: implications for precision medicine.

INTRODUCTION: Recent studies indicated tumors may be comprised of heterogeneous molecular subtypes and incongruent molecular portraits may emerge if different areas of the tumor are sampled. This study explored the impact of intra-tumoral heterogeneity in terms of activation/phosphorylation of FDA approved drug targets and downstream kinase substrates. MATERIAL AND METHODS: Two independent sets of liver metastases from colorectal cancer were used to evaluate protein kinase-driven signaling networks within different areas using laser capture microdissection and reverse phase protein array. RESULTS: Unsupervised hierarchical clustering analysis indicated that the signaling architecture and activation of the MAPK and AKT-mTOR pathways were consistently maintained within different regions of the same biopsy. Intra-patient variability of the MAPK and AKT-mTOR pathway were <1.06 fold change, while inter-patients variability reached fold change values of 5.01. CONCLUSIONS: Protein pathway activation mapping of enriched tumor cells obtained from different regions of the same tumor indicated consistency and robustness independent of the region sampled. This suggests a dominant protein pathway network may be activated in a high percentage of the tumor cell population. Given the genomic intra-tumoral variability, our data suggest that protein/phosphoprotein signaling measurements should be integrated with genomic analysis for precision medicine based analysis.

Pathological response after neoadjuvant bevacizumab- or cetuximab-based chemotherapy in resected colorectal cancer liver metastases.

Neoadjuvant chemotherapy (NACT) prior to liver resection is advantageous for patients with colorectal cancer liver metastases (CLM). Bevacizumab- or cetuximab-based NACT may affect patient outcome and curative resection rate, but comparative studies on differential tumour regression grade (TRG) associated with distinct antibodies-associated regimens are lacking. Ninety-three consecutive patients received NACT plus bevacizumab (n = 46) or cetuximab (n = 47) followed by CLM resection. Pathological response was determined in each resected metastasis as TRG rated from 1 (complete) to 5 (no response). Except for KRAS mutations prevailing in bevacizumab versus cetuximab (57 vs. 21 %, p = 0.001), patients characteristics were well balanced. Median follow-up was 31 months (IQR 17-48). Bevacizumab induced significantly better pathological response rates (TRG1-3: 78 vs. 34 %, p < 0.001) as well as complete responses (TRG1: 13 vs. 0 %, p = 0.012) with respect to cetuximab. Three-year progression-free survival (PFS) and overall survival (OS) were not significantly different in the two cohorts. At multivariable analysis, significant association with pathological response was found for number of resected metastases (p = 0.015) and bevacizumab allocation (p < 0.001), while KRAS mutation showed only a trend. Significant association with poorer PFS and OS was found for low grades of pathological response (p = 0.009 and p < 0.001, respectively), R2 resection or presence of extrahepatic disease (both p < 0.001) and presence of KRAS mutation (p = 0.007 and p < 0.001, respectively). Bevacizumab-based regimens, although influenced by the number of metastases and KRAS status, improve significantly pathological response if compared to cetuximab-based NACT. Possible differential impact among regimens on patient outcome has still to be elucidated.

TP53 mutations in advanced colorectal cancer: the dark side of the moon.

BACKGROUND: Evidence for TP53 mutations as biomarker in colorectal cancer (CRC) is conflicting. METHODS: We assessed TP53 mutations in 51 patients with advanced CRC enrolled into a phase II, randomised trial of first-line tegafur-uracil (UFT)/leucovorin (LV) plus irinotecan (n = 23) versus UFT/LV plus oxaliplatin (n = 28). RESULTS: Non-functional TP53 mutations were found in 35% of patients. The response rate was not significantly different according to TP53 status. Progression-free and overall survival were longer in patients with TP53 mutations compared to those with wild-type TP53 (9 vs. 6.5 months, p = 0.0504, and 39.2 vs. 19.6 months, p = 0.0055, respectively). On multivariable analysis, TP53 mutation was independently associated with a decreased risk of death (hazard ratio 0.329, 95% CI 0.159-0.679; p = 0.0026). Treatment arm did not interact with TP53 in influencing outcomes. CONCLUSION: TP53 was not predictive of benefit from first-line irinotecan- or oxaliplatin-based chemotherapy. TP53 mutations may possibly be associated with a more indolent course of CRC after the diagnosis of metastatic disease.

Role of BAX for outcome prediction in gastrointestinal malignancies.

Our group and numerous others have shown in both preclinical and clinical studies that the proapoptotic mediator BAX may be deregulated through gene mutation or loss of protein expression, affecting resistance to chemotherapy and radiotherapy in several cancer types. However, BAX is also involved in cancer development and may related to prognosis, independently of treatment outcome. The clinical impact of BAX status in gastrointestinal malignancies remains controversial, although it is generally hypothesized that high expression may be a positive prognostic factor and predict increased efficacy of chemotherapy (with particular regard to platinum derivatives). The present review aims to provide updated information on BAX as potential prognostic and/or predictive biomarker in gastroesophageal and colorectal cancers, as well as in other less studied gastrointestinal malignancies.

A modified vimentin histological score helps recognize pulmonary sarcomatoid carcinoma in small biopsy samples.

BACKGROUND: As pulmonary sarcomatoid carcinomas (PSCs) are life-threatening tumors, an improvement in their recognition in small-sized tumor samples is clinically warranted. MATERIALS AND METHODS: Preoperative biopsy samples and paired surgical specimens from 20 pleomorphic carcinomas, two pulmonary blastomas and one carcinosarcoma (training set) were studied for vimentin immunohistochemistry. A modified vimentin histologic score (M-VHS) was devised by multiplying three independently assessed parameters, i.e. the percentage of positive cells (from 0 to 5+, by quintiles), the intensity of immunostaining (low=1 vs. strong=2) and the distribution pattern within the cytoplasm (partial=1 vs. diffuse=2), so ranging from 0 to 20. Forty-eight consecutive and independent cases of non-small cell lung carcinoma (NSCLC), including two additional cases of PSC, were used as control groups (validation set). RESULTS: No differences in M-VHS were found between biopsies and surgical specimens of PSC, thus confirming the occurrence of stable epithelial mesenchymal transition (EMT) and hence the specific diagnosis of PSC. All types of PSC shared the same M-VHS. The M-VHS of 46 conventional NSCLC was by far lower (p<0.0001), whereas two additional cases of PSC showed the same results as the training set. Poorly differentiated NSCLC with marked pleomorphism but not stable EMT did not exhibit significantly increased M-VHS values. CONCLUSION: M-VHS helped in morphological analysis to render more definite diagnoses on small biopsies of PSC.

Succinate dehydrogenase B subunit immunohistochemical expression predicts aggressiveness in well differentiated neuroendocrine tumors of the ileum.

Immunohistochemical loss of the succinate dehydrogenase subunit B (SDHB) has recently been reported as a surrogate biomarker of malignancy in sporadic and familial pheocromocytomas and paragangliomas through the activation of hypoxia pathways. However, data on the prevalence and the clinical implications of SDHB immunoreactivity in ileal neuroendocrine tumors are still lacking. Thirty-one consecutive, advanced primary midgut neuroendocrine tumors and related lymph node or liver metastases from 24 males and seven females were immunohistochemically assessed for SDHB. All patients were G1 tumors (Ki-67 labeling index ≤2%). SDHB immunohistochemistry results were expressed as immunostaining intensity and scored as low or strong according to the internal control represented by normal intestinal cells. Strong positivity for SDHB, with granular cytoplasmatic reactivity, was found in 77% of primary tumors (T), whilst low SDHB expression was detected in 90% of metastases (M). The combined analysis (T+M) confirmed the loss of SDHB expression in 82% of metastases compared to 18% of primary tumors. SDHB expression was inversely correlated with Ki-67 labeling index, which accounted for 1.54% in metastastic sites and 0.7% in primary tumors. A correlation between SDHB expression loss, increased Ki-67 labeling index and biological aggressiveness was shown in advanced midgut neuroendocrine tumors, suggesting a role of tumor suppressor gene.