Antibiotic-exposed patients with non-small-cell lung cancer preserve efficacy outcomes following first-line chemo-immunotherapy.

BACKGROUND: Prior antibiotic therapy (pATB) is known to impair efficacy of single-agent immune checkpoint inhibitors (ICIs), potentially through the induction of gut dysbiosis. Whether ATB also affects outcomes to chemo-immunotherapy combinations is still unknown. PATIENTS AND METHODS: In this international multicentre study, we evaluated the association between pATB, concurrent ATB (cATB) and overall survival (OS), progression-free survival (PFS) and objective response rate (ORR) in patients with non-small-cell lung cancer (NSCLC) treated with first-line chemo-immunotherapy at eight referral institutions. RESULTS: Among 302 patients with stage IV NSCLC, 216 (71.5%) and 61 (20.2%) patients were former and current smokers, respectively. Programmed death-ligand 1 tumour expression in assessable patients (274, 90.7%) was ≥50% in 76 (25.2%), 1%-49% in 84 (27.9%) and <1% in 113 (37.5%). Multivariable analysis showed pATB-exposed patients to have similar OS {hazard ratio (HR) = 1.42 [95% confidence interval (CI): 0.91-2.22]; P = 0.1207} and PFS [HR = 1.12 (95% CI: 0.76-1.63); P = 0.5552], compared to unexposed patients, regardless of performance status. Similarly, no difference with respect to ORR was found across pATB exposure groups (42.6% versus 57.4%, P = 0.1794). No differential effect was found depending on pATB exposure duration (≥7 versus <7 days) and route of administration (intravenous versus oral). Similarly, cATB was not associated with OS [HR = 1.29 (95% CI: 0.91-1.84); P = 0.149] and PFS [HR = 1.20 (95% CI: 0.89-1.63); P = 0.222] when evaluated as time-varying covariate in multivariable analysis. CONCLUSIONS: In contrast to what has been reported in patients receiving single-agent ICIs, pATB does not impair clinical outcomes to first-line chemo-immunotherapy of patients with NSCLC. pATB status should integrate currently available clinico-pathologic factors for guiding first-line treatment decisions, whilst there should be no concern in offering cATB during chemo-immunotherapy when needed.

[Mycobacterium avium tumoral infection mimicking a lung adenocarcinoma: A potential diagnostic pitfall]. / Infection à Mycobacterium avium simulant un adénocarcinome pulmonaire : un potentiel piège diagnostique.

INTRODUCTION: The incidence of atypical mycobacterial infection in Europe is estimated at one case per 100,000 persons/year. Despite the low incidence of Mycobacterium avium infection, it can result in a nodular lesion simulating lung cancer. We report a case of atypical mycobacteriosis, mimicking lung cancer, which led to a lobectomy. CASE REPORT: It was a right pulmonary upper lobe nodule found in a 63-year-old COPD patient, partially nephrectomized for renal carcinoma, and weekly treated by methotrexate for rheumatoid arthritis. FDG uptake was weakly positive on PET-CT (SUV=2.2) in the upper fissure. Bronchoscopy yielded no lesions and no bacteriological findings. Percutaneous transthoracic lung biopsy revealed lung adenocarcinoma stage T1 (a) N0M0. An upper lobectomy with lymphadenectomy was performed. Histological examination revealed epithelioid granuloma surrounded by giant cells suggestive of tuberculomas. The bronchial washing fluid culture was positive for Mycobacterium avium after 7 weeks. CONCLUSION: In pseudo-neoplastic forms of atypical mycobacteriosis, the presence of alveolar, inflammatory cytonuclear abnormalities can mimic an adenocarcinoma. Making the difference between the cytonuclears defects related to inflammation or neoplasia remains a daily challenge in histopathology.

Histological and immunohistochemical revision of hepatocellular adenomas: a learning experience.

Light has been shed on the genotype/phenotype correlation in hepatocellular adenoma (HCA) recognizing HNF1 α -inactivated HCA (H-HCA), inflammatory HCA (IHCA), and ß -catenin-activated HCA (b-HCA). We reviewed retrospectively our surgical HCA series to learn how to recognize the different subtypes histopathologically and how to interpret adequately their immunohistochemical staining. From January 1992 to January 2012, 37 patients underwent surgical resection for HCA in our institution. Nine had H-HCA (25%) characterized by steatosis and loss of L-FABP expression; 20 had IHCA (55.5%) showing CRP and/or SAA expression, sinusoidal dilatation, and variable inflammation; and 1 patient had both H-HCA and IHCA. In 5 patients (14%), b-HCA with GS and ß -catenin nuclear positivity was diagnosed, two already with hepatocellular carcinoma. Two cases (5.5%) remained unclassified. One of the b-HCA showed also the H-HCA histological and immunohistochemical characteristics suggesting a subgroup of ß -catenin-activated/HNF1 α -inactivated HCA, another b-HCA exhibited the IHCA histological and immunohistochemical characteristics suggesting a subgroup of ß -catenin-activated/inflammatory HCA. Interestingly, three patients had underlying vascular abnormalities. Using the recently published criteria enabled us to classify histopathologically our retrospective HCA surgical series with accurate recognition of b-HCA for which we confirm the higher risk of malignant transformation. We also underlined the association between HCA and vascular abnormalities.