No abstract

An intrapulmonary teratoma (IPT), multiloculated and bronchiectatic, with two polyps inside a 23-year-old man is reported. The IPT, a very rare benign cystic lesion, was communicating with segmental bronchus and was removed by a segmental resection from the upper lobe of the left lung. The teratoma contained various kinds of primordial derivatives, such as mesoderm, ectoderm, and endoderm. Though 65 cases of IPT have been reported in the literature (1839-1996), in the present case there were over 15 germ derivatives, the largest number reported to date. The tumor contained thymic tissue, apart from mediastinum, which may be significant in relation to the pathogenesis of IPT. Clinical manifestations, age, and gender distributions and the kind of germ cell derivatives are discussed.

Bronchial artery infusion therapy has been performed in a total of 27 patients by a selective catheterization technique chiefly as surgical adjuvant chemotherapy. A major antitumor agent chosen for this study was Mitomycin C. There was apparent tumor regression on the chest roentgenograms in 14 of 27 cases. The extent of tumor shrinkage ranged from 75% at maximum to 36% at minimum in 2 dimensional measurements on the x‐ray films. The patients were treated 1 to 4 times in a period of 2 days to 2 weeks. Observation periods after final infusion were limited to the term of preoperation. Subjective complaints were improved by the treatment. No serious side effects and very few complications were experienced. The authors would like to point out that the extent of tumor shrinkage may be related to the frequency of the infusion, and distant survival rate seemed to be better with the patients who received cancer resection after having recurrent infusion than with the patients having only one infusion.

Pancreatic cancer is one of the most dangerous solid tumors, but its early diagnosis is difficult. The abnormality of the main pancreatic duct (MPD), such as a single localized stricture and upstream dilatation, might be useful in the early detection of pancreatic cancer. However, these findings are often observed in benign inflammatory cases. This study aimed to clarify whether early pancreatic cancer presenting MPD abnormalities has characteristic features different from those of benign cases. This is a single-center, retrospective study. We analyzed 20 patients who underwent pancreatectomy presenting with a single, localized MPD stricture without identifiable masses on imaging: 10 patients with pancreatic ductal adenocarcinoma (cancer group; 6 with stage 0 and 4 with stage I) and 10 patients with benign strictures (benign group; 8 with inflammation and 2 with low-grade pancreatic intraepithelial neoplasms). Pancreatectomy was performed in these benign cases because high-grade intraepithelial neoplasm was suspected. Although the proportion of patients with diabetes mellitus tended to be higher in the cancer group (6/10) than that in the benign group (1/10) (P = 0.058), other clinical characteristics were not different between the groups. Preoperative cytological malignancies were detected in four patients in the cancer group (4/10) but not in the benign group (P = 0.09). Focal parenchymal atrophy and fat replacement were more frequently detected on computed tomography in the cancer group (7/10) than in the benign group (1/10) (P = 0.02). In conclusion, focal parenchymal atrophy and fat replacement may provide clues for the early diagnosis of pancreatic cancer.

Noninvasive diagnostics using circulating tumor cells (CTCs) are expected to be useful for decision making in precision cancer therapy. AXL, a receptor tyrosine kinase is associated with tumor progression, epithelial‐to‐mesenchymal transition (EMT), and drug resistance, and is a potential therapeutic target. However, the epithelial markers generally used for CTC detection may be not enough to detect AXL‐expressing CTCs due to EMT. Here, we evaluated the detection of AXL‐expressing CTCs using the mesenchymal marker vimentin with a microcavity array system. To evaluate the recovery of cancer cells, spike‐in experiments were performed using cell lines with varying cytokeratin (CK) or vimentin (VM) expression levels. With high CK and low VM‐expressing cell lines, PC‐9 and HCC827, the recovery rate of AXL‐expressing cancer cells was 1%‐17% using either CK or VM as markers. Whereas, with low CK and high VM‐expressing cell lines, MDA‐MB231 and H1299, it was 52%‐75% using CK and 72%‐88% using VM as a marker. For clinical evaluation, peripheral blood was collected from 20 non–small cell lung cancer patients and CTCs were detected using CK or VM as markers in parallel. Significantly more AXL‐expressing single CTCs were detected in VM‐positive than CK‐positive CTCs (P < .001). Furthermore, CTC clusters were identified only among VM‐positive CTCs in 20% of patients. Patients with one or more prior treatments harbored significantly more VM‐positive AXL‐expressing CTCs, suggesting the involvement of these CTCs in drug resistance. These results indicate the necessity of integrating mesenchymal markers with CTC detection and this should be further evaluated clinically.

Although programmed death-ligand 1 (PD-L1) expression on tumor tissue is a validated predictive biomarker for a PD-1 pathway blockade in non-small cell lung cancer (NSCLC), longitudinal changes in its expression during treatment remains elusive. Circulating tumor cells (CTCs) are assumed to reflect the transition of characteristics of the primary tumor undergoing anticancer treatment. Here, we sequentially evaluated the PD-L1 expression on CTCs in NSCLC patients treated with nivolumab. Forty-five patients were enrolled, and CTCs were enriched from 3 mL of peripheral blood using a microcavity array system at baseline and weeks 4, 8, 12, and 24 or until progressive disease. The effective responses to therapy were compared between patients without progressive disease (PD) at week 8 (i.e., non-PD patients) and in those with PD between weeks 4 and 8 (PD patients) in terms of increased vs. decreased or equal CTC status at week 8 (for non-PD patients) or at the point of PD (for PD patients) compared to the baseline. Significantly more non-PD patients were classified as decreased or equal in number and proportion to PD-L1-positive CTCs among the detected CTCs (PD-L1 positivity rates) (p < 0.05). Moreover, progression-free survival was significantly longer in patients with ≥7.7% PD-L1 positivity rates (n = 8) than in those with <7.7% rates (n = 8; p < 0.01) at week 8. These results suggest the predictive significance of the early evaluation of PD-L1 expression on CTCs for maintaining the benefits from nivolumab treatment.

No abstract

Pancreatic ductal adenocarcinoma (PDAC) is highly lethal, and early diagnosis is challenging. Because patients who present with symptoms generally have advanced-stage diseases, analysis of asymptomatic PDAC provides invaluable information for developing strategies for early diagnosis. Here, we reviewed 577 patients with PDAC (372 diagnosed with symptoms [symptomatic group] and 205 without symptoms [asymptomatic group]) diagnosed at our institute. Among the 205 asymptomatic PDAC patients, 109 were detected during follow-up/work-up for other diseases, 61 because of new-onset or exacerbation of diabetes mellitus, and 35 in a medical check-up. Asymptomatic PDAC is characterized by smaller tumor size, earlier disease stage, and higher resectability than those of symptomatic PDAC. In 22.7% of asymptomatic cases, indirect findings, e.g., dilatation of the main pancreatic duct, triggered PDAC detection. Although pancreatic tumors were less frequently detected, overall abnormality detection rates on imaging studies were nearly 100% in asymptomatic PDAC. Asymptomatic PDAC had a better prognosis (median survival time, 881 days) than symptomatic PDAC (342 days, P < 0.001). In conclusion, diagnosis of PDAC in the asymptomatic stage is associated with early diagnosis and a better prognosis. Incidental detection of abnormal findings during the follow-up/work-up for other diseases provides important opportunities for early diagnosis of asymptomatic PDAC.