Diffusion-weighted imaging diagnostic algorithm in patients with suspected pleural malignancy

Objectives The purpose of this study was to analyze the diagnostic performance and clinical application of diffusion-weighted imaging (DWI) in patients with suspected pleural malignancy (PM). Methods A retrospective review of patients with suspected PM was performed from March 2014 to August 2018 (NCT 02320617). All patients underwent chest DWI and computed tomography (CT) with cytological or histopathological findings as reference standards. The diagnostic performance of DWI and CT was analyzed and compared. A DWI diagnostic algorithm with three sequential steps was established. Results Seventy patients (61.6 ± 13.6 years; 47 males and 23 females) were included. The sensitivity of DWI (94.2%, 49/52) for the diagnosis of PM was significantly higher compared with CT (67.3%, 35/52), with similar specificity (72.2% vs. 72.2%, respectively). The apparent diffusion coefficient of malignant lesions (1.15 ± 0.32 × 10−3 mm2/s) was lower compared with benign lesions (1.46 ± 0.68 × 10−3 mm2/s), but the cutoff value was difficult to define for overlap between groups. Approximately 62.5% (5/8) of invasive procedures were avoided when using the DWI diagnostic algorithm in patients with suspected PM without N3 lymph node or extra-thoracic metastasis. Conclusion Including DWI into the diagnostic algorithm of suspected PM can effectively identify malignancy and avoid unnecessary invasive procedures, which may have some potential in clinical application. Key Points • Diffusion-weighted imaging can identify pleural malignancy much more efficiently than CT. • A diffusion-weighted imaging diagnostic algorithm helped to avoid unnecessary invasive procedures in patients without N3 lymph node or extra-thoracic lesions. • A hyperintense signal on DWI at a high b value (800 s/mm2) but not at a low b value (50 s/mm2) was a reliable signature of PM.

Statistical approach to mediastinal staging in NSCLC with M.E.S.S.i.a. software

The exclusion of pathological involvement of mediastinal lymph nodes in patients affected by NSCLC plays a central role in assessing their prognosis and operability. Ceron et al. developed a software - called M.E.S.S.i.a (Mediastinal Evaluation with Statistical Support; instant approach) - that allows the calculation of the residual probability of lymph node involvement after a certain number of tests has been done, by integrating every test result with the pre-test prevalence. M.E.S.S.i.a. bridges a gap of current American College of Chest Physicians (ACCP) guidelines, providing probability values of mediastinal metastasis for a correct clinical decision. We conducted a preliminary retrospective study in a series of 108 patients affected by non small cell lung cancer (NSCLC). Pathological staging was compared to the probability of nodal involvement calculated by M.E.S.S.i.a. software. Forty-two out of 108 subjects (39%) had a calculated post-test probability <8%; none of these had proven N2/N3 metastasis at surgical staging (negative predictive value, NPV: 100%). In 12/41 cases M.E.S.S.i.a. was able to avoid invasive procedures. The remaining 66 (61%) patients did not reach the surgical threshold; among these, 11 displayed N2 positivity at pathological staging. Receiving operator curve (ROC) analysis produced an area under curve (AUC) value of 0.773 (p<0.001). These preliminary data show high accuracy of M.E.S.S.i.a. software in excluding N2/N3 lymph node involvement in NSCLC. We have therefore promoted a prospective multicenter study in order to to get a validation of the calculator at different levels of probability of lymph node involvement. The recruitable subjects are potentially operable NSCLC patients; the gold standard for detection of mediastinal disease is the surgical lymph node dissection.

Prognostic factors for pulmonary large-cell neuroendocrine carcinoma: a competing-risks analysis

Background Pulmonary large-cell neuroendocrine carcinoma (LCNEC) is a rare and highly invasive subtype of lung cancer that accounts for fewer than 3% of cases. The prognostic factors for pulmonary LCNEC are unclear in the literature. Methods Patients diagnosed with pulmonary LCNEC between 2004 and 2015 were identified in the Surveillance, Epidemiology, and End Results (SEER) database. The CumIncidence function was used for the univariate analysis. Multivariate analysis was performed using Cox regression analysis, subdistribution hazard function analysis, and cause-specific hazard function analysis. Results We finally screened 1246 patients diagnosed with pulmonary LCNEC, among whom 796 died of LCNEC and 141 died from other causes. The univariate analysis showed that sex, primary site, laterality, American Joint Committee on Cancer (AJCC) stage, T stage, N stage, M stage, lymph-node status, surgery, and chemotherapy were significant prognostic factors for pulmonary LCNEC (P<0.05). The multivariate analysis demonstrated that sex, AJCC stage, TNM stage T4, TNM stage N3, lymph-node status, surgery, and chemotherapy were independent risk factors for the prognosis (P<0.05). Conclusion We have conducted a competing-risks analysis of patients with pulmonary LCNEC in the SEER database. The results showed that sex, AJCC stage, TNM stage T4, TNM stage N3, lymph-node status, surgery, and chemotherapy are independent prognostic factors for pulmonary LCNEC patients. The reported data represent reference information that can be used for accurate assessments of the prognosis of pulmonary LCNEC patients.

The impact of pre-operative chemotherapy in patients with peritoneal lavage cytology positive or localized peritoneum metastasis for gastric cancer: A multicenter retrospective study.

95 Background: Peritoneal lavage cytology of positive and localized peritoneum metastasis of gastric cancer (GC) are defined as CY1 and P1 in the 14th edition of the Japanese Classification of GC. Patients (pts) with CY1 and/or P1 have poor prognosis after removing all macroscopically visible disease by standard gastrectomy followed by S1. The aim of this study was to investigate the efficacy of pre-operative chemotherapy (Pre-Cx) in patients with CY1 and/or P1. Methods: We retrospectively reviewed the GC pts who were diagnosed to have CY1 and/or P1 at 34 institutions participating in the Stomach Cancer Group of Japan Clinical Oncology Group between 2007 and 2012. Inclusion criteria were: no distant metastasis other than CY1 or P1, no prior treatment for GC. The subjects were divided to two groups according to treatment strategy with/without Pre-Cx before surgery. In the Pre-Cx group, status of CY and P was diagnosed by laparoscopy before and after Pre-Cx, and indication of surgical resection was decided by each physician. Results: A total of 824 pts were collected from 34 institutions. Of the 713 eligible pts, 150 pts received Pre-Cx (Pre-Cx group) and 563 pts underwent surgery followed by Cx (Post-Cx group). Proportions of P0CY1/P1CY0/P1CY1 were 69/12/19% and 69/17/14% in the Pre- and Post-Cx. Cx regimen for Pre-Cx were S1 plus cisplatin/ docetaxel and cisplatin plus S1/others (n=90/37/23). In the Pre-Cx, 57 (38%) pts who achieved P0CY0 after Pre-Cx showed better survival than the remaining 92 pts (overall survival (OS), 31.0 vs. 19.9 months (M), HR=1.99, 95% CI 1.32-2.93, p=0.001). OS was 24.8 and 24.0 M in the Pre- and Post-Cx (HR 1.07; 95% CI 0.87-1.32, p=0.502). In multivariate analysis, P1CY1, over 65 years old and clinical N3 lymph node metastasis were identified as the independent prognostic factor for OS (p<0.05). Conclusions: Although Pre-Cx showed favorable survival in case of achieving P0 and CY0, Pre-Cx did not show a survival benefit for GC pts with CY1 and /or P1.