Colorectal cancer treated by resection and extended lymphadenectomy: patterns of spread in left- and right-sided tumours

BACKGROUND

Whether tumour side affects the anatomical extent and distribution of lymph node metastasis in colon cancer is unknown. The impact of tumour side on the anatomical pattern of lymphatic spread in colon cancer was assessed.

METHODS

Patients with stage III colon cancer from a Japanese multi-institutional database who underwent extensive (D3) lymphadenectomy, which is similar in concept to complete mesocolic excision with central venous ligation, were divided into groups with right- and left-sided tumours. Based on location, mesenteric lymph nodes were categorized as paracolic (L1), intermediate (L2) or central (L3). The Kaplan-Meier method was used to evaluate disease-free survival (DFS) and overall survival (OS), and multivariable Cox models were used to evaluate the association between anatomical lymph node level, metastatic pattern and outcome.

RESULTS

A total of 4034 patients with stage III colon cancer (right 1618, left 2416) were included. Unadjusted OS was worse in patients with right colon cancer (hazard ratio 1·23, 95 per cent c.i. 1·08 to 1·40; P = 0·002), but DFS was similar. Right-sided tumours more frequently invaded L3 nodes than left-sided lesions (8·5 versus 3·7 per cent; P < 0·001). The proportion of patients with a skipped pattern of lymphatic spread was higher in right than in left colon cancer (13·7 versus 9·0 per cent; P < 0·001). In multivariable analysis, invasion of L3 nodes was associated with worse OS in left but not in right colon cancer. The presence of skipped metastasis was associated with worse DFS in left, but not right, colon cancer.

CONCLUSION

There are significant differences in the pattern of lymph node invasion between right- and left-sided stage III colon cancer, and in their prognostic significance, suggesting that tumour side may dictate the operative approach.

Effect of high ligation on survival of patients undergoing surgery for primary colorectal cancer and synchronous liver metastases

Background

Although R0 surgery is recommended for stage IV colorectal cancer, the degree of required lymphadenectomy has not been established. The aim of this study was to investigate the prognostic impact of high ligation (HL) of the feeding artery and the number of retrieved lymph nodes after R0 surgery for colorectal cancer and synchronous colorectal cancer liver metastasis (CRLM).

Methods

This was a multi‐institutional retrospective analysis of patients with colorectal cancer and synchronous CRLM who had R0 surgery between January 1997 and December 2007. Clinical and pathological features were compared in patients who underwent HL and those who had a low ligation (LL). Kaplan–Meier analysis was performed to estimate the effect of HL on overall survival (OS). The impact of several risk factors on survival was analysed using the Cox proportional hazards model.

Results

Of 549 patients, 409 (74·5 per cent) had HL. Median follow‐up was 51·4 months. HL significantly improved the 5‐year OS rate (58·2 per cent versus 49·3 per cent for LL; P = 0·017). Multivariable analysis revealed HL to be a significant prognostic factor compared with LL (5‐year mortality: hazard ratio (HR) 0·68, 95 per cent c.i. 0·51 to 0·90; P = 0·007). In subgroup analysis, the positive effect of HL on OS was greatest in patients with lymph node metastasis.

Conclusion

HL of the feeding artery was associated with improved OS in patients with colorectal cancer and synchronous CRLM after R0 surgery.

Nomograms predicting survival and recurrence in colonic cancer in the era of complete mesocolic excision

Background

More extensive lymphadenectomy may improve survival after resection of colonic cancer. Nomograms were created predicting overall survival and recurrence for patients who undergo D2-D3 lymph node dissection, and their validity determined.

Methods

This was a multicentre study of patients with colonic cancer who underwent resection with D2-D3 lymph node dissection in Japan. Inclusion criteria included R0 resection. A training cohort of patients operated on from 2007 to 2008 was analysed to construct prognostic models predicting survival and recurrence. Discrimination and calibration were performed using an external validation cohort from the Japanese colorectal cancer registry (procedures in 2005-2006).

Results

The training cohort consisted of 2746 patients. Predictors of survival were: age (hazard ratio (HR) 1·04), female sex (HR 0·71), depth of tumour invasion (HR 1·15, 1·22, 2·96 and 3·14 for T2, T3, T4a and T4b respectively versus T1), lymphatic invasion (HR 1·11, 1·15 and 2·95 for ly1, ly2 and ly3 versus ly0), preoperative carcinoembryonic antigen (CEA) level (HR 1·21, 1·59 and 1·99 for 5·1-10·0, 10·1-20·0 and 20·1 and over versus 0-5·0 ng/ml), number of metastatic lymph nodes (HR 1·07), number of lymph nodes examined (HR 0·98) and extent of lymphadenectomy (HR 0·23, 0·13 and 0·11 for D1, D2 and D3 versus D0). Predictors of recurrence were: female sex (HR 0·82), macroscopic type (HR 3·82, 4·56, 6·66, 7·74 and 3·22 for types I, II, III, IV and V versus type 0), depth of invasion (HR 1·25, 2·66, 5·32 and 6·43 for T2, T3, T4a and T4b versus T1), venous invasion (HR 1·43, 3·05 and 4·79 for v1, v2 and v3 versus v0), preoperative CEA level (HR 1·39, 1·43, 1·56 and 1·85 for 5·1-10·0, 10·1-20·0, 20·1-40·0 and 40·1 or more versus 0-5 ng/ml), number of metastatic lymph nodes (HR 1·07) and number of lymph nodes examined (HR 0·98). The validation cohort comprised 4446 patients. The internal and external validated Harrell's C-index values for the nomogram predicting survival were 0·75 and 0·74 respectively. Corresponding values for recurrence were 0·78 and 0·75.

Conclusion

These nomograms could predict survival and recurrence after curative resection of colonic cancer.

A method of producing genetically manipulated mouse mammary gland

Background

To obtain a deep understanding of the mechanism by which breast cancer develops, the genes involved in tumorigenesis should be analyzed in vivo. Mouse mammary gland can regenerate completely from a mammary stem cell (MaSC), which enables us to analyze the effect of gene expression and repression on tumorigenesis in mammary gland regenerated from genetically manipulated MaSCs. Although lentiviral and retroviral systems have usually been applied for gene transduction into MaSCs, they are associated with difficulty in introducing long, repeated, or transcriptional termination sequences. There is thus a need for an easier and quicker gene delivery system.

Methods

We devised a new system for gene delivery into MaSCs using the piggyBac transposon vectors and electroporation. Compared with viral systems, this system enables easier and quicker transfection of even long, repeated, or transcriptional termination DNA sequences. We designed gene expression vectors of the transposon system, equipped with a luciferase (Luc) expression cassette for monitoring gene transduction into regenerative mammary gland in mice by in-vivo imaging. A doxycycline (Dox)-inducible system was also integrated for expressing the target gene after mammary regeneration to mimic the actual mechanism of tumorigenesis.

Results

With this new gene delivery system, genetically manipulated mammary glands were successfully reconstituted even though the vector size was > 200 kb and even in the presence of DNA elements such as promoters and transcription termination sequences, which are major obstacles to viral vector packaging. They differentiated correctly into both basal and luminal cells, and showed normal morphological change and milk production after pregnancy, as well as self-renewal capacity. Using the Tet-On system, gene expression can be controlled by the addition of Dox after mammary reconstitution. In a case study using polyoma-virus middle T antigen (PyMT), oncogene-induced tumorigenesis was achieved. The histological appearance of the tumor was highly similar to that of the mouse mammary tumor virus-PyMT transgenic mouse model.

Conclusions

With this system, gene transduction in the mammary gland can be easily and quickly achieved, and gene expression can be controlled by Dox administration. This system for genetic manipulation could be useful for analyzing genes involved in breast cancer.

Electronic supplementary material

The online version of this article (10.1186/s13058-018-1086-8) contains supplementary material, which is available to authorized users.

Prognostic impact of interhospital variation in adjuvant chemotherapy for patients with Stage II/III colorectal cancer: a nationwide study

AIM

Clinical guidelines recommend adjuvant chemotherapy for high-risk patients with Stage II-III colorectal cancer. However, chemotherapeutic administration rates differ significantly between hospitals. We assessed the prognostic benefit of adjuvant chemotherapy in patients with Stage IIb/c colorectal cancer, and the prognostic impact of interhospital variations in the administration of adjuvant chemotherapy for Stage II-III colorectal cancer.

METHOD

We conducted a multicentre, retrospective study of 17 757 patients with Stage II-III colorectal cancer treated between 1997 and 2008 in 23 hospitals in Japan. Hospitals were classified as high-rate (rate > 42.8%) or low-rate (rate ≤ 42.8%), chemotherapy prescribing clinics.

RESULTS

The 5-year overall survival (OS) of patients with Stage II-III colorectal cancer receiving adjuvant chemotherapy was significantly higher than for those not receiving adjuvant chemotherapy (85.7% vs 79.2%, P < 0.01 and 79.9% vs 72.5%, P < 0.01, respectively). For patients with Stage II disease, adjuvant chemotherapy was an independent factor for longer OS (P < 0.01, hazard ratio = 0.71). Both adjuvant chemotherapy and high-rate hospital independently improved OS for patients with Stage III colorectal cancer (both P < 0.01; hazard ratio = 0.68 and 0.87, respectively).

CONCLUSION

Significant prognostic benefit was found for patients with Stage IIb/c colorectal cancer who received adjuvant chemotherapy, with patients who were treated in hospitals with high adjuvant chemotherapy rates demonstrating better prognoses.

Prognostic value of tropomyosin-related kinases A, B, and C in gastric cancer

PURPOSE

Tropomyosin-related kinase (Trk) receptors play critical roles in tumor development and are considered attractive targets for cancer therapy. We investigated correlations of the expression of TrkA, TrkB, and TrkC with clinicopathological features and outcomes in gastric cancer.

METHODS

Tumor samples were obtained from 221 patients with gastric cancer who underwent gastrectomy between 2003 and 2007. The expression of TrkA, TrkB, and TrkC was analyzed using immunohistochemical staining. The relationship of their expression to clinicopathological factors and outcomes was assessed.

RESULTS

High expression of TrkA, TrkB, or TrkC was significantly associated with histopathology (p = 0.022, p < 0.001, and p < 0.001). High expression of TrkA was significantly correlated with variables related to tumor progression, including lymph node metastasis (p = 0.024) and distant metastasis or recurrence (p < 0.001). Distant metastasis or recurrence was found in a significantly higher proportion of patients with high expression of TrkC than in those with low expression (p = 0.036). High expression of TrkA was significantly associated with poorer relapse-free survival (RFS) in univariate analysis (p = 0.001). High expression of TrkA or TrkC was significantly associated with poorer disease-specific survival (DSS) in univariate analysis (p < 0.001 and p = 0.008). In multivariate analysis, TrkA was an independent predictor of RFS [hazard ratio (HR), 2.294; 95 % confidence interval (CI), 1.309-4.032; p = 0.004] and DSS (HR, 2.146; 95 % CI, 1.195-3.861; p = 0.011). Expression of TrkB was not associated with RFS or DSS in univariate analysis.

CONCLUSIONS

Our results demonstrated that TrkA expression was associated with tumor progression and poor survival, and was an independent predictor of poor outcomes in gastric cancer patients.

Impact of revisions of the JSCCR guidelines on the treatment of T1 colorectal carcinomas in Japan

Purpose: In 1977, the Japanese Society for Cancer of the Colon and Rectum (JSCCR) published the first edition of the general guidelines that described how to record clinical and histopathological findings of colorectal carcinomas (CRCs) and how to treat these cancers, and since then, the guidelines were revised several times. The aim of this study was to examine the impact of the revisions of the JSCCR guidelines on the treatment of submucosal CRCs (T1-CRCs) in Japanese clinical settings.

Methods: Questionnaires were sent to all 391 member institutions of the JSCCR. The questionnaires consisted of 2 parts: details of the institutions and treatment strategies for T1-CRCs.

Results: 73 (19 %) institutions responded to the survey. The number of treated T1-CRCs has increased year by year, and the rate of endoscopic resection for T1-CRCs has significantly increased with revisions of the guidelines (1417 [47 %] of 2985 T1-CRCs in 2003 – 2005, 2110 [50 %] of 4212 in 2006 – 2008, and 2546 [54 %] of 4686 in 2009 – 2011, P<.05).

Conclusion: The revisions of the JSCCR guidelines have influenced the treatment of T1-CRCs in Japanese clinical settings. There is room to revise the criteria for curative endoscopic resection to avoid unnecessary surgeries.

Tumour characteristics, treatment patterns and survival of patients aged 80 years or older with colorectal cancer

AIM

This study aimed to clarify tumour characteristics and treatment patterns for patients with colorectal cancer aged 80 years or older and the impact of age on survival using a large-scale cancer registry database.

METHOD

The database was used to identify 40 851 colorectal cancer patients who underwent surgery between 1995 and 2004. Patients were stratified into four age groups (< 50, 50-64, 65-79, ≥ 80 years). Demographics, tumour characteristics, treatment pattern and survival were compared between age groups. Additionally, the impact of lymph node dissection and adjuvant chemotherapy on survival was studied using the propensity score-matching method.

RESULTS

In the over 80 age group, patients were more commonly female, with right colon cancer, multiple primary cancers, history of colorectal cancer, high serum carcinoembryonic antigen values, large tumour, undifferentiated histology, and more frequent pT3/pT4 tumours. In contrast, metastatic disease, central lymph node dissection and adjuvant chemotherapy were less frequent. Overall survival and cancer-specific survival decreased with increasing age for any stage. Multivariate analysis showed age to be an independent predictor of overall survival (hazard ratio 1.45, 95% CI 1.34-1.58, P < 0.001). In the propensity score-matched cohort, overall survival of the patients with central node dissection and having adjuvant chemotherapy was significantly better than for those without. This difference was not statistically significant in patients aged 80 and above.

CONCLUSION

This study showed a significant difference in tumour characteristics and treatment patterns in patients aged 80 and above. Even after adjustment for clinicopathological factors, the difference in survival persisted and age was considered a robust prognostic factor.

The AURKA/TPX2 axis drives colon tumorigenesis cooperatively with MYC

BACKGROUND

The MYC oncogene has long been established as a central driver in many types of human cancers including colorectal cancer. However, the realization of MYC-targeting therapies remains elusive; as a result, synthetic lethal therapeutic approaches are alternatively being explored. A synthetic lethal therapeutic approach aims to kill MYC-driven tumors by targeting a certain co-regulator on the MYC pathway.

PATIENTS AND METHODS

We analyzed copy number and expression profiles from 130 colorectal cancer tumors together with publicly available datasets to identify co-regulators on the MYC pathway. Candidates were functionally tested by in vitro assays using colorectal cancer and normal fibroblast cell lines. Additionally, survival analyses were carried out on another 159 colorectal cancer patients and public datasets.

RESULTS

Our in silico screening identified two MYC co-regulator candidates, AURKA and TPX2, which are interacting mitotic regulators located on chromosome 20q. We found the two candidates showed frequent co-amplification with the MYC locus while expression levels of MYC and the two genes were positively correlated with those of MYC downstream target genes across multiple cancer types. In vitro, the aberrant expression of MYC, AURKA and TPX2 resulted in more aggressive anchorage-independent growth in normal fibroblast cells. Furthermore, knockdown of AURKA or TPX2, or treatment with an AURKA-specific inhibitor effectively suppressed the proliferation of MYC-expressing colorectal cancer cells. Additionally, combined high expression of MYC, AURKA and TPX2 proved to be a poor prognostic indicator of colorectal cancer patient survival.

CONCLUSIONS

Through bioinformatic analyses and experiments, we proposed TPX2 and AURKA as novel co-regulators on the MYC pathway. Inhibiting the AURKA/TPX2 axis would be a novel synthetic lethal therapeutic approach for MYC-driven cancers.

S-1 as adjuvant chemotherapy for stage III colon cancer: a randomized phase III study (ACTS-CC trial)

BACKGROUND

S-1 is an oral fluoropyrimidine whose antitumor effects have been demonstrated in treating various gastrointestinal cancers, including metastatic colon cancer, when administered as monotherapy or in combination chemotherapy. We conducted a randomized phase III study investigating the efficacy of S-1 as adjuvant chemotherapy for colon cancer by evaluating its noninferiority to tegafur-uracil plus leucovorin (UFT/LV).

PATIENTS AND METHODS

Patients aged 20-80 years with curatively resected stage III colon cancer were randomly assigned to receive S-1 (80-120 mg/day on days 1-28 every 42 days; four courses) or UFT/LV (UFT: 300-600 mg/day and LV: 75 mg/day on days 1-28 every 35 days; five courses). The primary end point was disease-free survival (DFS) at 3 years.

RESULTS

A total of 1518 patients (758 and 760 in the S-1 and UFT/LV group, respectively) were included in the full analysis set. The 3-year DFS rate was 75.5% and 72.5% in the S-1 and UFT/LV group, respectively. The stratified hazard ratio for DFS in the S-1 group compared with the UFT/LV group was 0.85 (95% confidence interval: 0.70-1.03), demonstrating the noninferiority of S-1 (noninferiority stratified log-rank test, P < 0.001). In the subgroup analysis, no significant interactions were identified between the major baseline characteristics and the treatment groups.

CONCLUSION

Adjuvant chemotherapy using S-1 for stage III colon cancer was confirmed to be noninferior in DFS compared with UFT/LV. S-1 could be a new treatment option as adjuvant chemotherapy for colon cancer.

CLINICALTRIALSGOV

NCT00660894.

Incorporation of apical lymph node status into the seventh edition of the TNM classification improves prediction of prognosis in stage III colonic cancer

Background

The node classification outlined in the seventh edition of the TNM classification is based solely on the number of metastasized lymph nodes. This study examined the prognostic value of apical lymph node (ALN) metastasis and the additional value of incorporating ALN status into a risk model based on the seventh edition.

Methods

This was a cohort study of patients with stage III colonic cancer who underwent tumour resection with dissection of regional (including apical) lymph nodes at 71 hospitals across Japan between 2000 and 2002. The main exposure was pathologically confirmed ALN metastasis, and the primary endpoint was cancer-specific death.

Results

ALN metastasis was present in 113 (8·3 per cent) of 1355 patients. During 5356 patient-years of follow-up (median 5·0 years), 221 instances (16·3 per cent) of cancer-specific death were observed. After adjustment for tumour and node classification (as described in the seventh edition of the TNM classification) and other prognostic factors, ALN metastasis was found to be independently associated with cancer-specific death (hazard ratio 2·29, 95 per cent confidence interval (c.i.) 1·49 to 3·52). Incorporation of ALN metastasis into the prognostic model based on the seventh edition of the TNM classification significantly improved discriminative performance for cancer-specific death (difference in concordance index 0·0146, 95 per cent c.i. 0·0030 to 0·0262) and risk reclassification for cancer-specific death at 5 years (category-free net reclassification improvement 19·4 (95 per cent c.i. 5·0 to 33·4) per cent).

Conclusion

Assessment of ALN metastasis provided independent prognostic information beyond that achievable with the seventh edition of the TNM classification in patients with stage III colonic cancer.

Patterns, timing and risk factors of recurrence of gastric cancer after laparoscopic gastrectomy: reliable results following long-term follow-up

BACKGROUND

To clarify the patterns, timing and risk factors of recurrence of gastric cancer after laparoscopic gastrectomy.

METHODS

From January 1999 to March 2012, 577 patients underwent laparoscopic or laparoscopy-assisted gastrectomy for curative resection of gastric cancer. Recurrence patterns were classified as locoregional, hematogenous, peritoneal, distant lymph node and mixed. Recurrence patterns and time to recurrence were retrospectively examined and risk factors for recurrence were analyzed.

RESULTS

Recurrence occurred in 28 (4.9%) cases with patterns as follows: locoregional in 2 patients (7.1%), hematogenous in seven (25.0%), peritoneal in nine (32.1%), distant lymph node in four (14.3%), and mixed in 6 (21.4%). There was no recurrence pattern peculiar to laparoscopic surgery. Recurrence occurred at one site in 21 patients (78.6%), two in 4 patients (14.3%), and three in 2 patients (7.1%). The median time to recurrence was 384 days (range 83-1497 days). Recurrence was detected within a year in 13 cases (46.4%), within two years in 21 (75%), and within three years in 25 (89.3%). Univariate analysis revealed tumor location, tumor size, type of operation, tumor depth, and lymph node classification as risk factors for recurrence. Multivariate analysis indicated tumor depth and lymph node classification as risk factors of recurrence.

CONCLUSIONS

Patterns, timing and risk factors of recurrence of gastric cancer after laparoscopic gastrectomy are similar to those after open gastrectomy, with no peculiarities specific to laparoscopic gastrectomy. Thus, as long as laparoscopic gastrectomy is performed according to the present inclusion criteria, follow-up can be similarly performed as for open gastrectomy.