Serial circulating tumour DNA analysis for locally advanced rectal cancer treated with preoperative therapy: prediction of pathological response and postoperative recurrence

BACKGROUND

The "watch-and-wait" approach is a common treatment option amongst patients with locally advanced rectal cancer (LARC). However, the diagnostic sensitivity of clinical modalities, such as colonoscopy and magnetic resonance imaging to determine pathological response, is not high. We analysed the clinical utility of circulating tumour DNA (ctDNA) of patients with LARC to predict response to preoperative therapy and postoperative recurrence.

METHODS

A serial ctDNA analysis of 222 plasma samples from 85 patients with LARC was performed using amplicon-based deep sequencing on a cell-free DNA panel covering 14 genes with over 240 hotspots.

RESULTS

ctDNA was detected in 57.6% and 22.3% of samples at baseline and after preoperative treatment, respectively, which was significantly different (P = 0.0003). Change in ctDNA was an independent predictor of complete response to preoperative therapy (P = 0.0276). In addition, postoperative ctDNA and carcinoembryonic antigen (CEA) were independent prognostic markers for risk of recurrence after surgery (ctDNA, P = 0.0127 and CEA, P = 0.0105), with a combined analysis having cumulative effects on recurrence-free survival (P = 1.0 × 10^-16).

CONCLUSIONS

Serial ctDNA analysis may offer clinically useful predictive and prognostic markers for response to preoperative therapy and postoperative recurrence in patients with LARC.

Laparoscopic right hemicolectomy for a colon cancer patient with an ileal conduit

Here, we describe our experience of laparoscopic surgery in a colon cancer patient with an ileal conduit. To our knowledge, this is the second case presented in the English-language literature. A 71-year-old woman with a history of both open anterior exenteration with ileal conduit reconstruction for bladder cancer and open cholecystectomy for cholecystitis was diagnosed with ascending colon cancer (cT3N1M0). Laparoscopic right hemicolectomy with conduit preservation was planned. After adhesiolysis, complete mesocolic excision and central vascular ligation were achieved laparoscopically without injury to the conduit or other structures. Laparoscopic surgery for patients with an ileal conduit can be technically demanding. A preoperative plan based on preoperative imaging and the patient's previous operative record is crucial, especially when considering the optimal balance between oncological radicality and functional outcomes.

A retrospective analysis of ramucirumab monotherapy in previously treated Japanese patients with advanced or metastatic gastric adenocarcinoma

BACKGROUND

The REGARD trial demonstrated that ramucirumab monotherapy improved both overall survival (OS) and progression-free survival (PFS) compared with best supportive care plus placebo as second-line treatment for patients with advanced gastric cancer. However, the efficacy and safety of ramucirumab monotherapy for previously treated Japanese patients with advanced gastric cancer remains unknown.

METHODS

Previously treated Japanese patients with advanced gastric cancer who received ramucirumab monotherapy between June 2015 and March 2016 at the Cancer Institute Hospital were enrolled in the study. OS, PFS, best overall response, and safety profiles were retrospectively evaluated.

RESULTS

Nineteen patients were enrolled in this study. Ramucirumab monotherapy was generally administered as third-line therapy. After a median follow-up period of 7.4 months, the median PFS was 2.1 months (95% CI 1.0-3.5), and median OS was 12.9 months (95% CI 2.3, not reached). In 13 patients who had measurable lesions on radiologic examination, partial response was observed in one patient (7.7%) and stable disease was observed in five patients (38.5%). A total of 12 patients (63.2%) had adverse events (AEs). Common AEs included hypertension (8 patients, 42.1%), fatigue (6 patients, 31.6%), and bleeding (5 patients, 26.3%). Grade 3 AEs included gastrointestinal bleeding and aspiration pneumonia (1 patient each, 5.3%).

CONCLUSIONS

Our data suggest that ramucirumab monotherapy in Japanese patients with previously treated advanced gastric cancer has comparable efficacy and safety profiles as reported in the REGARD trial.

[A Case of Lymph Node Metastasis of Rectal Laterally Spreading Tumor with Mucosal Cancer after Endoscopic Submucosal Dissection]

A screening fecal occult blood test was positive in a 76-year-old female. Colonoscopy showed laterally spreading tumor (LST)over 15 cm at lower rectum. endoscopic submucosal dissection(ESD)was performed. Pathological findings showed LST-G, 150×100 mm, adenocarcinoma(tub1-tub2), tubular adenoma, moderate-severe atypia, Tis(M), ly(-), v(-), HMX, VMX. Two years later CT detected one swollen lymph node at mesorectum and PET-CT showed FDG up take at the lymph node. We diagnosed lymph node metastasis, performed laparoscopic very low anterior resection. Pathological findings showed one lymph node metastasis, but there were no residual cancer at rectum. We cut the surgical specimen at 5mm intervals because of it's big size. It might be impossible with this procedure to detect SM invasion at this specimen.

[Safety of Laparoscopic Surgery after Preoperative Short Course Radiotherapy for Lower Rectal Cancer]

BACKGROUNDS

In the setting of routine use of preoperative chemoradiotherapy(CRT)for cStage II / III rectal cancer, shortcourse radiotherapy(short-RT)is selectively used for reducing local recurrence.The purpose of this study is to clarify the safety of laparoscopic surgery after preoperative short-RT for lower rectal cancer.

METHODS

Twenty-eight patients who un- derwent short-RT followed by laparoscopic total mesorectal excision for cStage II / III lower rectal cancer were retrospectively analyzed.

RESULTS

The reasons for selecting short-RT included comorbidity(n=10), refusal of CRT(n=8), multiple cancers (n=6)and others(n=4).All patients completed planned dose of radiation without severe acute toxicity.Median interval from completion of short-RT to surgery was 17 days(range 7-58).All patients underwent laparoscopic surgery without conversion to open surgery.Median operation time, blood loss and the number of dissected lymph nodes were 379 minutes (range 175-890), 90mL(range 0-1,185)and 27(range 12-71), respectively.Grade 3-4 complications occurred in 3 cases (10.7%).There were 2 cases with pathological complete response.

CONCLUSIONS

Laparoscopic surgery for lower rectal cancer after short-RT is safe and feasible.

[A Case with Metastatic Huge Ovarian Tumor from Transverse Colon Cancer, Who Underwent Systemic Chemotherapy after Bilateral Oophorectomy and Right Hemi Colectomy]

Metastatic ovarian tumors from colon cancer would be resistant to chemotherapy, and compromising quality of life(QOL) of these patients was caused by acute enlargement of the tumors. A 37-year-old woman with abdominal distension was diagnosed with transverse colon cancer, bilateral ovarian metastases, liver metastases, and peritoneal dissemination at prior hospital. Two courses of chemotherapy(FOLFOX)were administered, but metastaticovarian tumors enlarged. Chemotherapy was discontinued and she was referred to our institution. To achieve symptom relief, improving QOL, and to resume chemotherapy, we planned bilateral oophorectomy and primary tumor resection if other stenotic lesion was not present. As a result, we safely performed open bilateral oophorectomy and right hemi colectomy, and the patient discharged on postoperative day 11 without complications. Chemotherapy was resumed and continued for 7 months up to this time. Even though, curative resection could not be achieved, oophorectomy should be performed in patients with enlarged metastatic ovarian tumor from colon cancer, in spite of administration of chemotherapy.

Case review for ramucirumab as a single agent in our hospital

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Background: Ramucirumab is approved in the USA, EU, and Japan as second-line treatment in advanced gastric or gastroesophageal junction adenocarcinoma. This agent is often used with paclitaxel, but we can use it as a single agent in second-line treatment. Because REGARD trial has shown that Ramucirumab as a single agent prolongs overall survival and progression-free survival. However, this trial doesn’t include Japanese patients, and we have no trial concerning the efficacy of Ramucirumab as third or later-line treatment up to date. We reviewed retrospectively the efficacy and safety of Ramucirumab as a single agent in our hospital. Methods: We investigated 12 cases from June (when Ramucirumab has been approved) to September. Results: The median age was 61 years old, 6 male and 6 female patients. Performance status (0/1/2) = (1/10/1) cases. (second/third/fourth or later)-lines = (4/4/4) cases. Metastatic sites are lymph node, liver, lung, bone, and peritoneum. 7 patients had gastrectomy and 5 patients of them received adjuvant chemotherapy. Response rate is 50%, median progressive-free survival is 51 days, and median overall survival is 13 months. Some patients experienced grade 1or 2 adverse events: fatigue, loss of appetite, diarrhea, and hypertension. Conclusions: We cannot say that single agent administration of Ramucirumab demonstrates good response, some patients kept stable disease in this regimen. Ramucirumab as a single agent can be an option of treatments after paclitaxel fails or when it is difficult to administrate it.

Rhodium complex-catalyzed reaction of isonitriles with carbonyl compounds: catalytic synthesis of pyrroles

[figure: see text] Low-valent rhodium complexes are efficient catalysts for the activation of alpha-C-H bond of isonitriles. Addition of isonitriles to carbonyl compounds proceeds under mild and neutral conditions to give the corresponding alpha,beta-unsaturated formamides. Catalytic synthesis of pyrroles can be performed by cyclocondensation of isonitriles with 1,3-dicarbonyl compounds.

Low-valent ruthenium and iridium hydride complexes as alternatives to Lewis acid and base catalysts

The discovery of a new chemical reaction often leads to new applications and new chemical principles. Low-valent ruthenium and iridium hydride complexes are highly useful redox Lewis acid and base catalysts. Nitriles are activated by these catalysts and undergo reactions with either nucleophiles or electrophiles under neutral conditions. Hydration of nitriles, esterification of nitriles with alcohols, and amidation of nitriles with amines can be performed catalytically together with formation of ammonia. The catalytic reactions of pronucleophiles such as nitriles and carbonyl compounds with electrophiles such as alkenes, alkynes, carbonyl compounds, imines, and nitriles take place generally.

Differentiation of smooth muscle cells from undifferentiated cells of chicken gizzard occurs on the layer of fibroblast-like cells

We examined the in vitro differentiation of smooth muscle cells from undifferentiated cells of embryonic chicken gizzard. We used the gizzard from 7-day-old embryos (Hamburger and Hamilton's stage 26-28) as a source of culture, since the expression of myosin is extremely low, and the gizzard consists of round cells, which are not stained by anti-smooth muscle myosin antiserum. When the dissections of the gizzard were cultured, they attached to the dish, and fibroblast-like cells migrated within 4 days after the culture. Then round cells migrated from the transplants over the layer of fibroblast-like cells. At 12-14 days after the culture, smooth muscle cells, which were ribbon-shaped and stained by anti-smooth muscle myosin antiserum, appeared in the layer of round cells. The dissected transplant itself was not stained by anti-smooth muscle myosin antiserum even after being cultured for 15 days. We concluded then that the smooth muscle cells were differentiated from the round cells, which spread on the layer of the fibroblast-like cells. We also observed the differentiation of smooth muscle cells when the cells separated from 7-day-old embryo cultured on the layer of cloned fibroblast cells. We suggest that the fibroblast-like cell may play an important role in the differentiation of smooth muscle cells.