Short- and long-term outcomes of transanal decompression tube and self-expandable metallic stent for obstructive colorectal cancer based on a multicenter database (KYCC2110)

AIM

There are well-known methods for decompressing the colorectal tract before surgery, including transanal decompression tubes (TDT) and self-expanding metallic stents (SEMS). This study aimed to compare the short and long-term results in patients with malignant large bowel obstruction in whom TDT or SEMS were placed before surgery.

METHODS

This retrospective observational study enrolled 225 patients with malignant large bowel obstruction in whom TDT or SEMS were placed preoperatively and underwent R0 resection between 2008 and 2020. One-to-two propensity score matching was performed according to patient characteristics. Short- and long-term outcomes were compared. The primary endpoint was relapse-free survival (RFS). The secondary endpoints were the overall survival (OS) and postoperative complication rate.

RESULTS

Fifty-seven patients in the TDT group and 114 in the SEMS group were matched. The 3-year RFS rates were 66.7% in the TDT group and 69.9% in the SEMS group (p = 0.54), and the 3-year OS rates were 90.5% in the TDT group and 87.1% in the SEMS group (p = 0.52). No significant differences in the long-term results were observed between the two groups. Regarding short-term results, the SEMS group had significantly fewer stoma construction (p = 0.007) and shorter postoperative hospitalization (p < 0.001). The incidence of postoperative complications (grade ≥ 2) was significantly lower in the SEMS group (p = 0.04).

CONCLUSION

No significant differences in the long-term results were observed between the TDT and SEMS group. The SEMS showed significant usefulness in terms of improving short-term outcomes.

Chemotherapy-induced Reversion of Mutant RAS to Wild-type RAS in Metastatic Colorectal Cancer

BACKGROUND/AIM

Secondary mutation of mutated RAS, induced by chemotherapy, is thought to be rare. However, introduction of liquid biopsy (LB) has made it possible to monitor RAS status in patients' plasma throughout the course of chemotherapy for metastatic colorectal cancer (mCRC), and disappearance of the RAS mutation (RAS-mt), i.e., the NeoRAS-wt phenomenon, has been reported and is receiving attention, especially with respect to treatment implications.

PATIENTS AND METHODS

A prospective study of 129 patients undergoing chemotherapy for mCRC (RAS-wt, n=65; RAS-mt, n=64) was carried out. Plasma RAS status was monitored in these patients by LB. Relations between secondary genetic change, chemotherapy, and 6-month disease outcomes were analyzed. The effect of anti-EGFR mAb therapy on NeoRAS-wt mCRC was also examined.

RESULTS

NeoRAS-wt was detected in 27 (43.5%) RAS-mt patients overall and in all patients with a G12S or Q61H mutation. First-line treatment was more effective among NeoRAS-wt patients than non-NeoRAS-wt patients (70.9% vs. 48.6% overall response rate, p=0.087), and the time from treatment to LB was shorter in this group. Six-month outcomes were significantly better in the NeoRAS-wt group (p<0.001), and conversion to NeoRAS-wt was found to be predictive of a good outcome (OR=7.886, 95% CI=2.458-25.30; p<0.001). Anti-EGFR mAb therapy was found to restrict disease progression in NeoRAS-wt patients.

CONCLUSION

Conversion to NeoRAS-wt is relatively frequent, and it may predict good responses to treatment. Anti-EGFR mAb therapy was effective for our NeoRAS-wt patients. Detection of NeoRAS-wt by LB may significantly change the indication for anti-EGFR mAb therapy and the mCRC treatment strategy.

Prediction of lateral lymph node metastasis using OSNA method for mesorectal lymph nodes in low rectal cancer: A prospective study by the Kanagawa Yokohama Colorectal Cancer Study Group (KYCC1801)

BACKGROUND AND OBJECTIVES

Contrary to the Japanese guidelines recommendations regarding lateral lymph node dissection (LatLND) for rectal cancer, its omission is common in clinical practice without reliable omission criteria. Negative pathological mesorectal lymph node metastasis (MesLNM) is reportedly highly correlated with negative pathological lateral lymph node metastasis (p-LatLNM); however, this cannot be used as a criterion because pathological features are revealed postoperatively. Herein, we prospectively evaluated the negative predictive value (NPV) of MesLNM diagnosed via the one-step nucleic acid amplification (OSNA) method for p-LatLNM.

METHODS

This prospective study was conducted at a single academic study group in Japan. The key eligibility criterion was mid-to-low rectal cancer planned to be treated using mesorectal excision with LatLND. According to the study protocol, the OSNA method was considered useful if the point estimate of the NPV exceeded 95%.

RESULTS

Preoperative case registration was conducted between 2018 and 2020; 34 patients were registered. Among these, 16 were negative for OSNA-MesLNM, and negative p-LatLNM was confirmed in all cases. The point estimate of the NPV was 100%, with the 95% confidence interval ranging from 79.4% to 100.0%.

CONCLUSIONS

The OSNA method is useful in selecting patients in whom LatLND can be omitted in real-world clinical practice.

Prospective analysis of tumor spread to the small bowel mesentery in cases of right-sided colon cancer

PURPOSE

Guidelines advocate minimal ileal resection when right hemicolectomy is performed for right-sided colon cancer. The practice, thought to prevent malabsorption syndrome, does not appear to foster local recurrence. Little evidence based on rigorous study exists, however. To understand the pattern of lymphatic spread of right-sided colon cancer toward the small bowel and thus determine the appropriate margin size, we prospectively investigated anatomical distribution of lymph nodes (LNs) in the small bowel mesentery and of metastasis to these nodes in patients with right-sided colon cancer treated by such surgery.

METHODS

In each case, the mesenteric specimen, which had been dissected along the ileocolic vessels and included intermediate LNs, was divided into 2 areas: that 0-3 cm from the vessel pedicle (area 1) and that 3-5 cm from the pedicle (area 2). The peri-intestinal mesentery was cut into 9 segments.

RESULTS

Ninety-one patients were included in the study. Overall, 3366 LNs were dissected. Four hundred fifty-three of these LNs were located in area 1 (90 cases), and 15 (3.3%) were metastatic. Only 63 LNs were located in area 2 (34 cases; average of 0.69 per patient); none was metastatic. Overall, 269 LNs were found in the small bowel mesentery (in 56 of the 91 patients). Only 4 were positive (3 cases), and all were within 5 cm of the ileocecal valve.

CONCLUSION

Our data indicate that a surgical margin 3 cm from the ileocecal pedicle and a short (5 cm) ileal margin are oncologically reasonable for effective right hemicolectomy.

Clinical analysis of multiple primary malignancies of the hypopharynx and esophagus

PURPOSE

Because the capability to control squamous cell carcinomas of the head and neck has improved recently, the phenomenon of multiple primary malignancies of that region is now recognized with increasing frequency. We reviewed cases of multiple primary squamous cell carcinomas of the hypopharynx and esophagus with regard to their frequency, incidence, and prognosis.

PATIENTS AND METHODS

We reviewed 104 cases of hypopharyngeal cancer to determine (1) if and when esophageal cancer occurred, (2) the classification of multiple tumors as metachronous or synchronous, and (3) tumor histology.

RESULTS

In most cases of the metachronous type, esophageal cancer followed hypopharyngeal cancer within less than 3 years. Most cases of hypopharyngeal cancer were at an advanced stage, in contrast to esophageal cancer, which were all early stage. These cases had a poor prognosis despite various treatments causing local disease to be well controlled. Endoscopic esophageal mucosal resection was found to be an effective treatment for esophageal cancer, especially in superficial types.

CONCLUSIONS

The prognosis and mild systemic damage after endoscopic esophageal mucosal resection compare favorably with surgery, radiation, or systemic chemotherapy.

Treatment of malignant melanoma of the lower eyelid using anterolateral thigh flap

Malignant melanoma is a poor prognostic disease with the potential for high mortality despite early diagnosis and currently available treatment. Surgical judgment pertaining to the extent of primary resection and regional node dissections must be tempered by cosmetic considerations and by the anatomically diffuse pathways for lymphatic spread in certain lesions. We reported a case of malignant melanoma of the left lower eyelid, and presented the surgical excision and reconstruction using anterolateral thigh flap for skin defect. It is evident that comprehensive treatment using radical surgery and adjuvant chemotherapy is necessary for cutaneous malignant melanoma of head and neck areas.

Cyclin D1 and p53 overexpression predicts multiple primary malignant neoplasms of the hypopharynx and esophagus

BACKGROUND

Multiple primary upper aerodigestive tract carcinomas can occur in up to 15% of patients. We have shown previously that half of the patients with multiple upper aerodigestive tract squamous cell carcinomas are initially seen with synchronous tumors. Most metachronous squamous cell carcinomas become manifest within 3 years.

OBJECTIVE

To examine the expression of 2 proteins-cyclin D1 and p53--in an attempt to predict the occurrence of multiple primary malignant neoplasms (MPs).

MATERIALS AND METHODS

Monoclonal antibodies to cyclin D1 (DCS-6 [dilution, 1:50]. Novocastra Laboratories Ltd, Newcastle, England) and p53 (DO-7 [dilution, 1-100], Dako Corp, Carpinteria, Calif) proteins were used. Resection specimens from a total of 47 patients, 12 patients with MP and 35 patients with nonmultiple primary malignant neoplasms, were analyzed. Those in the nonmultiple primary malignant neoplasm group had longer than 3 years' follow-up to ascertain the absence of MP.

RESULTS

Tumor overexpression of cyclin D1 was significantly associated with the development of MP (P<.01). Tumor overexpression of p53 was also frequent in patients with MP although statistical significance was not achieved. The combination of these 2 parameters was an even greater predictor of MP (P<.001).

CONCLUSIONS

Overexpression of cyclin D1 and p53 proteins was highly correlated with the development of MP. Additional studies are necessary to confirm this finding. Immunohistochemical evaluation of primary squamous cell carcinomas for cyclin D1 and p53 overexpression may become an important fact of surgical pathologic reporting for primary upper aerodigestive tract squamous cell carcinomas.

Solitary fibrous tumor of the paranasal sinuses

Although solitary fibrous tumors are well-recognized in the pleura, their occurrence in the paranasal sinuses is decidedly uncommon. We have encountered two cases of solitary fibrous tumors in the paranasal sinuses and report the clinicopathological findings including CD34 immunoreactivity. One tumor arose in a 55-year-old Japanese businessman and the other in a 53-year-old man who had been in the hospital for schizophrenia for 20 years. The tumors showed characteristic findings. Immunoperoxidase stains on paraffin sections showed staining of the cells for anti-vimentin, but there was no staining for anti-keratin, anti-S-100 protein, anti-desmin, anti-glial fibrillary acidic protein (GFAP), or anti-actin. Anti-CD34 monoclonal antibodies also reacted with these tumors, as those of the pleura generally do, and were found to be useful in diagnosing these tumors. CD34 immunoreactivity [8]. Fukunaga et al. [6] reported that CD34 immunoreactivity presented in a solitary fibrous tumor of the nasal cavity, but separate tumors of the paranasal sinuses have not been analyzed. We have recently encountered two cases of solitary fibrous tumors of the paranasal sinuses. In this report, the clinicopathological features of these tumors of and their CD34 immunoreactivity were analyzed.

[An immunohistochemical study of RB tumor suppressor gene protein and bcl-2 gene protein in carcinomas of the thyroid gland]

The expression of RB and bcl-2 proteins was investigated in 135 thyroid carcinomas (130 papillary carcinomas and five follicular carcinomas) by the immunohistochemical technique with RB and bcl-2 monoclonal antibodies. The results were as follows: 1) RB protein nuclear staining was shown in 117 of the 135 thyroid carcinomas (87%). Bcl-2 protein staining was shown in 82 of the carcinomas (61%). 2) There was a higher incidence of recurrence in RB-negative cases than in RB-positive cases (chi 2 test p = 0.001). But there is no significant relationship between the incidence of recurrence and the results of bcl-2 staining (chi 2 test p = 0.287). 3) The expression of RB protein was related to age and clinical N and M categories. Bcl-2 protein expression was related to clinical T categories. 4) The 10-year overall survival rate for RB-positive patients was higher than that for negative patients (long-rank test p < 0.0001). But the survival rate was not associated with bcl-2 expression (log-rank test p = 0.3). Our results suggest that assessment of RB protein expression by the immunohistochemical technique may be useful to determine the possibility of recurrence and to predict the outcome of thyroid carcinomas. We think that assessment of RB protein expression by the immunohistochemical technique can be applied as a more sensitive prognostic factor.

[Pharmacological studies on experimental nephritic rats (11). Changes in pathohistological and biochemical parameters in anti-rat GBM rabbit serum-induced nephritis (author's transl)]

Anti-rat glomerular basement membrane (GBM) rabbit serum was produced by immunizing rabbits with the supernatant substance of trypsin-digested rat GBM. Nephritis was induced in rats by a single intravenous administration of 0.25 ml of anti-serum and changes in pathohistological and biochemical parameters during the process of the disease were investigated in comparison with those of Masugi nephritis and the modified type of Masugi nephritis previously reported. In light microscopic studies, histological changes seen in the kidneys closely resembled those of typical human glomerulonephritis. Changes such as hypercellularity, adhesion between capillary wall and Bowman's capsule, crescent formation and hyalinization in glomeruli and interstitial infiltration were the most pronounced on the 30th day after the anti-serum injection. In immunofluorescent studies, a linear fixation of rabbit IgG was observed along the GBM from the 1st day and the staining of a certain intensity was preserved throughout the experimental periods. A linear staining with anti-rat IgG serum was recognized from the 10th day. The fixation of fibrinogen was also seen in not only the glomerular capillary walls, but also in Bowman's space after the 10th day. Proteinuria significantly increased from the 1st day, reached a peak of 12 times the control level, and thereafter gradually decreased. The patterns of progress of urinary alkaline phosphatase and N-acetyl-beta-glucosaminidase activities were much the same as those seen in cases of proteinuria and the levels at their peak times were about 10 and 3 times control levels, respectively. Plasma urea nitrogen level transiently increased on the 5th day and then reverted to the control level by the 30th day. Plasma cholesterol levels were significantly high from the 5th to the 20th days. It is concluded that glomerular damages in this model are more severe, so-called, "nephritic type" and continue for longer periods than in cases of Masugi nephritis, however, do not differ in degree and duration from findings in the modified type of Masugi nephritis.