Conversion surgery for initially unresectable locally advanced pancreatic ductal adenocarcinoma after chemotherapy followed by carbon-ion radiotherapy: a case report

BACKGROUND

Recent advances in chemotherapy and chemoradiotherapy have enabled conversion surgery (CS) to be performed for selected patients with initially unresectable locally advanced (LA) pancreatic ductal adenocarcinoma (PDAC). Many studies indicate CS might extend the survival of patients with initially unresectable LA PDAC. However, several clinical questions concerning CS remain, such as the optimal preoperative treatment. Carbon-ion radiotherapy (CIRT) is a unique radiotherapy that offers higher biological effectiveness than conventional radiotherapy. Here, we report a long-term survival case with initially unresectable LA PDAC who underwent CS after chemotherapy followed by CIRT.

CASE PRESENTATION

The patient was a 72-year-old Japanese woman with unresectable LA pancreatic head cancer with tumor contact to the superior mesenteric artery (SMA). She underwent four courses of chemotherapy (gemcitabine plus nanoparticle albumin-bound paclitaxel). However, the lesion did not shrink and tumor contact with the SMA did not improve after chemotherapy. Because the probability of achieving curative resection was judged to be low, she underwent radical dose CIRT, and chemotherapy was continued. She complained of vomiting 2 months after CIRT. Although imaging studies showed no tumor growth or metastasis, a duodenal obstruction which was speculated to be an adverse effect of CIRT was observed. She could not eat solid food and a trans-nasal feeding tube was inserted. Therapeutic intervention was required to enable enteral nutrition. We proposed several treatment options. She chose resection with the expectation of an anti-tumor effect of chemotherapy and CIRT rather than course observation with tube feeding or bypass surgery. Therefore, subtotal-stomach-preserving pancreatoduodenectomy with portal vein resection was performed as CS. Pathological examination of the resected specimen revealed an R0 resection with a histological response of Evans grade IIA. Postoperatively, she recovered uneventfully. Adjuvant chemotherapy with tegafur/gimeracil/oteracil (S1) was administrated. At the time of this report, 5 years have passed since the initial consultation and she has experienced no tumor recurrence.

CONCLUSIONS

The present case suggests that multidisciplinary treatment consisting of a combination of recent chemotherapy and CIRT may be beneficial for unresectable LA PDAC. However, further studies are required to assess the true efficacy of this treatment strategy.

Mixed neuroendocrine-non-neuroendocrine neoplasm of the ampulla of Vater: a case report

BACKGROUND

Mixed neuroendocrine-non-neuroendocrine neoplasms of the ampulla of Vater are rare and heterogenous, making it difficult to achieve a definitive preoperative diagnosis. Herein, we describe a patient in whom a provisional diagnosis of mixed neuroendocrine-non-neuroendocrine neoplasm of the ampulla of Vater was made preoperatively.

CASE PRESENTATION

Computed tomography revealed an enhancing periampullary tumor in a 69-year-old man with obstructive jaundice. Subsequent duodenoscopy revealed an ulcerated lesion in the swollen ampulla of Vater, from which six biopsies were collected. Pathological examination revealed adenocarcinoma in five of them. The remaining one was a neuroendocrine neoplasm according to immunohistochemical analysis. With a provisional diagnosis of mixed neuroendocrine-non-neuroendocrine neoplasm of the ampulla of Vater, the patient underwent subtotal stomach-preserving pancreaticoduodenectomy with modified Child's reconstruction and was discharged without complications. Pathological examination revealed both adenocarcinoma and neuroendocrine carcinomas, each accounting for ≥ 30% of the tumor, resulting in a definitive diagnosis of mixed neuroendocrine-non-neuroendocrine neoplasm of the ampulla of Vater. Lymph node metastases with neuroendocrine components were also observed. Adjuvant chemotherapy was not administered because of the patient's renal dysfunction. Liver and lymph node metastases were detected 2 months after surgery, the neuroendocrine component being considered responsible for that relapse. The patient underwent platinum-based chemotherapy at 50% dosage, which initially resulted in significant tumor shrinkage; however, he died 6 months after surgery.

CONCLUSIONS

While these tumors' heterogeneity make definitive preoperative diagnosis of mixed neuroendocrine-non-neuroendocrine neoplasm of the ampulla of Vater difficult, the possibility of this disease can be considered by careful examination. Further study is needed to establish the optimal diagnostic criteria and treatment strategy.

Cancer-derived cholesterol sulfate is a key mediator to prevent tumor infiltration by effector T cells

Effective tumor immunotherapy requires physical contact of T cells with cancer cells. However, tumors often constitute a specialized microenvironment that excludes T cells from the vicinity of cancer cells, and its underlying mechanisms are still poorly understood. DOCK2 is a Rac activator critical for migration and activation of lymphocytes. We herein show that cancer-derived cholesterol sulfate (CS), a lipid product of the sulfotransferase SULT2B1b, acts as a DOCK2 inhibitor and prevents tumor infiltration by effector T cells. Using clinical samples, we found that CS was abundantly produced in certain types of human cancers such as colon cancers. Functionally, CS-producing cancer cells exhibited resistance to cancer-specific T-cell transfer and immune checkpoint blockade. Although SULT2B1b is known to sulfate oxysterols and inactivate their tumor-promoting activity, the expression levels of cholesterol hydroxylases, which mediate oxysterol production, are low in SULT2B1b-expressing cancers. Therefore, SULT2B1b inhibition could be a therapeutic strategy to disrupt tumor immune evasion in oxysterol-non-producing cancers. Thus, our findings define a previously unknown mechanism for tumor immune evasion and provide a novel insight into the development of effective immunotherapies.

Pathologic complete response after gemcitabine and S-1 chemotherapy for far advanced intrahepatic cholangiocarcinoma

We report the case of a 72-year-old man who was initially diagnosed with far advanced intrahepatic cholangiocarcinoma, associated with bulky lymph node metastasis involving the common hepatic artery and moderate amount of ascites around the liver. After 10 cycles of systemic chemotherapy combining gemcitabine and S-1 with well-tolerated toxicities, a CT scan showed a marked shrinkage of the liver mass and lymph nodes (clinical partial response) with disappearance of ascites, which could permit a radical resection of the tumor. He underwent left lobectomy of the liver with lymph node dissection, and histopathological examination revealed pathologic complete response. Seven years after surgery, he is in a good overall condition.

[Multiple extracranial metastases from meningioma treated with surgical resection - a case report]

A 73-year-old woman underwent a craniotomy for an atypical meningioma in 1993, and underwent re-excision for local recurrence 4 years later. In 2008, a chest X-ray film revealed 2 nodules in the right lung. A wedge resection of S2 and a middle lobectomy of the right lung were performed. Pathological findings indicated that the 2 tumors originated from the intracranial meningioma resected in 1993. In 2013, a computed tomography (CT) scan demonstrated hypervascular masses in the liver (S4), pancreatic body, and lower portion of the right kidney. She underwent partial hepatectomy, distal pancreatectomy, and partial nephrectomy, and the final diagnosis was hepatic, pancreatic, and renal metastases from meningioma. After 10 months, a transcatheter arterial embolization (TAE) was performed for hepatic recurrence (S5). She is presently doing well, 5 months after TAE, without any signs of recurrence.

A new method of determining the solute permeability of hollow-fiber dialysis membranes by means of laser lights traveling along optic fibers

To develop a new method of determining solute permeability more simply and accurately, the authors employed light from a laser traveling along quartz optic fibers. Dialysis experiments at 310 K were made with a single hollow fiber containing aqueous test solutes. A membrane tube was sealed at either end with quartz optic fibers. Helium-neon and helium-cadmium laser lights emitted from one of these optic fibers into the test solution at wavelengths of 543 and 442 nm for vitamin B12 and cytochrome-C, respectively, were caught by the other optic fiber and detected with a silicon photodiode. The solute permeability for cytochrome-C obtained by this method was almost in agreement with that for beta-2-microglobulin by the radioisotope method. This study demonstrates the usefulness of light from a laser traveling along quartz optic fibers in determining the solute permeability of hollow-fiber dialysis membranes.

Removal of beta-2-microglobulin by diffusion alone is feasible using highly permeable dialysis membranes

Techniques of filtration with high flux dialysis membranes are capable of easily removing beta-2-microglobulin (beta-2-M) (MW: 11,800) from renal failure patients. However, hemodialysis is preferred as a method of removing beta-2-M in terms of cost and operation. The present study elucidates the permeability characteristics for beta-2-M of newly developed cellulosic and synthetic polymer membranes for hemodialysis to determine the diffusive clearance for beta-2-M. The authors did dialysis experiments with 3H-labeled water and 125I-labeled beta-2-M to obtain the solute permeability of cellulosic and synthetic polymer membranes. Radioactivity of a single hollow fiber after dialysis experiments for predetermined periods was measured in a gamma counter. Through analysis of radioactivity data, they obtained solute permeability data, from which diffusive clearance for beta-2-M was calculated. With wet cellulose triacetate membranes, values for inside diameter, wall thickness, and water content were 205 +/- 10 microns (N = 100), 12.4 +/- 1.5 microns (N = 200), and 78 vol%, respectively. The cellulose triacetate membranes had a solute permeability for beta-2-M of (4.12 +/- 1.83) x 10(-5) cm/sec (N = 25) and a pure water permeability of 60 ml/m2/hr/mmHg. Diffusive clearance for beta-2-M was calculated to be 39 ml/min at a plasma flow rate of 160 ml/min and a dialysate flow rate of 500 ml/min. The diffuse clearance of capillary dialyzers composed of regenerated cellulose and synthetic polymer membranes ranged from 23 to 19 ml/min.(ABSTRACT TRUNCATED AT 250 WORDS)