Recommendations for the reporting of surgically resected specimens of colorectal carcinoma

The impact of lymph node ratio on overall survival in patients with colorectal cancer

Background

Lymph node metastasis is a predominant prognostic indicator in colorectal cancer. Number of lymph nodes removed surgically was demonstrated to correlate with staging accuracy and oncological outcomes. However, number of lymph nodes removed depends on uncontrolled variables. Therefore, a more reliable prognostic indicator is needed. Calculation of ratio of positive lymph nodes to total number of removed lymph nodes may be an appealing solution.

Materials and Methods

We retrospectively analyzed data of 156 Stage III colorectal cancer patients whom underwent surgery between 2008 and 2015. Patients' demographic characteristics, tumor grade, location, vascular-perineural invasion status, number of removed lymph nodes, and ratio of positive lymph nodes to number of removed lymph nodes were recorded. Spearman correlation analysis was used to determine the correlation coefficient while Kaplan-Meier method and Cox proportional hazard regression model were performed for the prediction of survival and multivariate analysis, respectively.

Results

Number of removed lymph nodes did not correlate with survival, but it was inversely correlated with number of positive lymph nodes. Multivariate analysis showed that ratio of removed positive lymph nodes to the total number of lymph nodes was a significant prognostic factor for survival for a ratio equal or above 0.31 was a poor prognostic indicator (108 months vs. 34 months, hazard ratio: 4.24 [95% confidence interval: 2.15-8.34]; P < 0.019). Tumor characteristics failed to demonstrate any prognostic value.

Conclusions

This study showed that positive lymph node ratio (PLNR) is an important prognostic factor for Stage III colorectal cancer. Although 0.31 can be taken as threshold for "PLNR," prospective trials including larger patient groups are needed to validate its role as a prognostic indicator.

Histopathology of locally advanced colorectal carcinoma, with emphasis on tumor invasion of adherent peritoneal membranes

Locally advanced colorectal carcinomas are characterized by neoplastic cells that invade beyond the colon and directly into surrounding organs and structures that include the retroperitoneum and abdominopelvic sidewall. These aggressive tumors are prognostically adverse and are categorized with highest possible tumor stage in current cancer staging systems. Recognizing colorectal carcinoma with extensive locoregional invasion is typically straightforward, but some cases can be diagnostically challenging. These include tumors with limited invasion of extracolonic tissue such as the subserosa in which there are no cells or structures that are histologically or architecturally distinct from the colonic primary. Tumor-associated injury of the colonic peritoneum often precedes invasion by the neoplastic cells and can cause the peritoneal membrane of the colon to adhere and subsequently fuse to the peritoneal membrane of a neighboring organ or structure, thereby creating a trans-peritoneal bridge through which a tumor can directly invade the adherent extracolonic tissue. Hence, locally advanced colorectal carcinoma can be narrowly defined by neoplastic cells that completely invade through the fused peritoneal membrane and into the subserosa of the adherent extracolonic tissue. The evaluation of tumor invasion of the fused peritoneal membrane, which is enhanced by the combined use of an elastic stain and an immunostain for pan-keratin, is essential for the proper staging of locally advanced colorectal carcinoma and its clinical management.

Down-staging depth score to predict outcomes in locally advanced rectal cancer achieving ypI stage after neoadjuvant chemo-radiotherapy versus de novo stage pI cohort: A propensity score-matched analysis

Objective

Prognosis of patients with locally advanced rectal cancer (LARC) but achieving ypT1-2N0 stage after neoadjuvant concurrent chemo-radiotherapy (CRT) has been shown to be favorable. This study aims to determine whether the long-term outcome of ypT1-2N0 cases can be comparable to that of pT1-2N0 cohort that received definitive surgery for early disease.

Method

From January 2008 to December 2013, 449 consecutive patients with rectal cancer were treated and their outcome maintained in a database. Patients with LARC underwent total mesorectal excision (TME) surgery at 4-8 weeks after completion of CRT, and those achieving stage ypI were identified as a group. As a comparison, stage pI group pertains to patients whose initially limited disease was not upstaged after TME surgery alone. After propensity score matching (PSM), comparisons of local regional control (LC), distant metastasis-free survival (DMFS), disease-free survival (DFS) and overall survival (OS) were performed using Kaplan-Meier analysis and log-rank test between ypI and pI groups. Down-staging depth score (DDS), a novel method of evaluating CRT response, was used for subset analysis.

Results

Of the 449 patients, 168 matched cases were generated for analysis. Five-year LC, DMFS, DFS and OS for stage pI vs. ypI groups were 96.7% vs. 96.4% (P=0.796), 92.7% vs. 73.6% (P=0.025), 91.2% vs. 73.6% (P=0.080) and 93.1% vs. 72.3% (P=0.040), respectively. In the DDS-favorable subset of the ypI group, LC, DMFS, DFS and OS resulted in no significant differences in comparison with the pI group (P=0.384, 0.368, 0.277 and 0.458, respectively).

Conclusions

LC was comparable in both groups; however, distant metastasis developed more frequently in down-staged LARC than de novo early stage cases, reflecting the need to improve the efficacy of systemic treatment despite excellent pathologic response. DDS can be an indicator to identify a subset of the ypI group whose long-term oncologic outcomes are as good as those of stage pI cohort.

Tumor Budding, uPA, and PAI-1 in Colorectal Cancer: Update of a Prospective Study

Aims. The prognostic role of the proteases uPA and PAI-1, as well as tumor budding, in colon cancer, has been investigated previously. Methods. We provide 6-year follow-up data and results of the validation set. The initial test set and validation set consisted of 55 colon cancers and 68 colorectal cancers, respectively. Tissue samples were analyzed for uPA and PAI-1 using a commercially available Enzyme-Linked Immunosorbent Assay (ELISA). Tumor budding was analyzed on cytokeratin-stained slides. Survival analyses were performed using cut-offs that were determined previously. Results. uPA was not prognostic for outcome. PAI-1 showed a trend towards reduced cancer specific survival in PAI-1 high-grade cases (68 versus 83 months; P = 0.091). The combination of high-grade PAI-1 and tumor budding was associated with significantly reduced cancer specific survival (60 versus 83 months; P = 0.021). After pooling the data from both sets, multivariate analyses revealed that the factors pN-stage, V-stage, and a combination of tumor budding and PAI-1 were independently prognostic for the association with distant metastases. Conclusions. A synergistic adverse effect of PAI-1 and tumor budding in uni- and multivariable analyses was found. PAI-1 could serve as a target for anticancer therapy.

Stage migration vs immunology: The lymph node count story in colon cancer

Lymph node staging is of crucial importance for the therapy stratification and prognosis estimation in colon cancer. Beside the detection of metastases, the number of harvested lymph nodes itself has prognostic relevance in stage II/III cancers. A stage migration effect caused by missed lymph node metastases has been postulated as most likely explanation for that. In order to avoid false negative node staging reporting of at least 12 lymph nodes is recommended. However, this threshold is met only in a minority of cases in daily practice. Due to quality initiatives the situation has improved in the past. This, however, had no influence on staging in several studies. While the numbers of evaluated lymph nodes increased continuously during the last decades the rate of node positive cases remained relatively constant. This fact together with other indications raised doubts that understaging is indeed the correct explanation for the prognostic impact of lymph node harvest. Several authors assume that immune response could play a major role in this context influencing both the lymph node detectability and the tumor’s behavior. Further studies addressing this issue are need. Based on the findings the recommendations concerning minimal lymph node numbers and adjuvant chemotherapy should be reconsidered.

Tumor Budding Is Independently Predictive for Lymph Node Involvement in Early Gastric Cancer

BACKGROUND

The most important prognostic factor for early gastric cancer (EGC) is the lymph node status. It is important to predict early lesions without lymph node metastasis (LNM) before proceeding to radical surgery in locally excised lesions. Tumor budding is a feature known to be related to aggressive tumor behavior in several solid tumors. We aimed to assess the predictive value of tumor budding for LNM in pT1a and pT1b gastric cancer.

METHODS

We retrospectively investigated radical gastrectomy specimens for of 126 EGC patients and assess the possible relation between the clinicopathologic features, including age, gender, tumor location, tumor size, macroscopic tumor type, histologic differentiation, depth and width of submucosal invasion, lymphovascular invasion, and tumor budding with lymph node involvement.

RESULTS

Among the 126 EGCs, 38 were stages as pT1a and 88 as pT1b. LNM rate in pT1a tumors was 13% whereas it was 33% in pT1b tumors. Tumor budding was the only factor significantly and independently related to LNM in pT1a patients. Female gender and tumor budding were found to be independent risk factors in pT1b group. Other clinicopathologic features were not related to LNM.

CONCLUSION

Based on these results, we suggest that budding is a promising parameter to assess for prediction of LNM in EGC removed by endoscopic surgery, and to decide on the appropriate surgical approach.

Tumor budding in colorectal carcinoma: time to take notice

Tumor 'budding', loosely defined by the presence of individual cells and small clusters of tumor cells at the invasive front of carcinomas, has received much recent attention, particularly in the setting of colorectal carcinoma. It has been postulated to represent an epithelial-mesenchymal transition. Tumor budding is a well-established independent adverse prognostic factor in colorectal carcinoma that may allow for stratification of patients into risk categories more meaningful than those defined by TNM staging, and also potentially guide treatment decisions, especially in T1 and T3 N0 (Stage II, Dukes' B) colorectal carcinoma. Unfortunately, its universal acceptance as a reportable factor has been held back by a lack of definitional uniformity with respect to both qualitative and quantitative aspects of tumor budding. The purpose of this review is fourfold: (1) to describe the morphology of tumor budding and its relationship to other potentially important features of the invasive front; (2) to summarize current knowledge regarding the prognostic significance and potential clinical implications of this histomorphological feature; (3) to highlight the challenges posed by a lack of data to allow standardization with respect to the qualitative and quantitative criteria used to define budding; and (4) to present a practical approach to the assessment of tumor budding in everyday practice.

Surgeons' Evaluation of Colorectal Cancer Resections Against Standard HPE Protocol-Auditing the Surgeons

The survival of Colorectal Cancer patients is very much dependent on complete tumor resection and multimodality adjuvant treatment. However, the main determinants for management plan of these patients rely heavily on accurate staging through histopathological examination (HPE). A reliable standard HPE protocol will be a significant impact in determining best surgical outcome. We evaluate surgeons' intra-operative judgment and the quality of resected specimens in the treatment of colorectal cancers. To quantify the quality of surgery by applying standard HPE protocol in colorectal cancer specimens and to assess the use of new format for pathological reporting in Colorectal Cancer using a formulated standard proforma. We perform a prospective observation of all colorectal cancer patients who underwent surgical resection over 8 month duration. Surgeons are required to make self-assessment about completion of tumor excision and possible lymph nodes or adjacent organ involvement while all pathologists followed standard reporting protocol for examination of the specimens. We evaluate the accuracy of surgeons judgment against HPE. The study involved 44 colorectal cancers comprising of 23 male and 21 female patients. The majority of these patients were Malay (50%) followed by Chinese (43%) and Indian (7%). The main presenting symptoms were bleeding (32%), intestinal obstruction (29%) and perforation (7%). Sixteen (36%) patients underwent emergency surgery.Rectal tumor was the commonest (53%) followed by sigmoid colon (22.7%). Neoadjuvant Chemoradiation were given to 8 patients and complete pathological response was observed in 1 (12.5%) of these. The final TNM classification for staging were; stage I (22.7%), stage IIa (18.2%), stage IIb (11.4%), stage IIIa (2.3%), stage IIIb (25%), stage IIIc (13.6%) and stage IV (6.8%).The commonest surgery performed was anterior resection with mesorectal excision (43.2%). Ten patients (22.7%) had laparoscopic surgery with 3 (30%) patients converted to open surgery. The surgeons claimed to have performed a curative resection with complete excision and clear margin in 40 (90%) patients. Of these, only 1 (2.5%) patient had a positive resection margin. Meanwhile, the surgeons reported involvement of resection margins in 4 cases but this was disputed by the HPE in all 4 cases. Lymph nodes involvement was detected intra-operatively in 13 (29.5%) of the cases and all were proven positive for metastases through HPE. On the other hand, of the remaining 31 patients who were reported as no obvious lymphadenopathy by the surgeons, lymph nodes positvity was found in 7 (22.5%) cases. Using standard HPE reporting protocol brings suitable evaluation of surgery in colorectal cancer treatment. Although surgeons' judgment is fairly accurate in predicting margin clearance and complete specimen excision, complete mesocolic and mesorectal excision is of utmost importance since lymph nodes metastatic involvement may not be obvious at surgery.

Individualized magnetic resonance imaging-based neoadjuvant chemoradiation for middle and lower rectal carcinoma

AIM

In most institutions neoadjuvant chemoradiation for middle and lower rectal carcinoma is currently given to patients with tumours of clinical stages II or III (cT3,4 and/or N1,2). The possibility of a reduction in the use of neoadjuvant chemoradiation by an individualized magnetic resonance imaging (MRI)-based indication for neoadjuvant chemoradiation was analysed.

METHOD

Assessment of the pathological and oncological principles indicating for neoadjuvant treatment was used to determine the prognostic importance of the distance between the tumour and the circumferential resection margin and pretherapeutic assessment using modern MRI.

RESULTS

Based on the results of pretreatment MRI scanning, a proposal is presented for the treatment of middle and lower rectal carcinoma with neoadjuvant chemoradiation. Adopting this proposal, the frequency of neoadjuvant chemoradiation decreased from 70% to 35% and the early and late adverse effects of this therapy were reduced. In contrast, the expected locoregional recurrence rate increased from 6% to 11% if all quality criteria were met and to 18% if not.

CONCLUSION

An MRI-based indication for neoadjuvant chemoradiation is justified only for centres with regular quality assurance of MRI, surgery, radiotherapy and pathology. The proposal needs confirmation by long-term follow up and by prospective studies with larger numbers of patients.

Association between histological type of tumour growth and patient survival in t2-t3 lymph node-negative rectal cancer treated with sphincter-preserving total mesorectal excision

For rectal cancer patients without nodal metastases the identification of unfavourable factors can be helpful for the better selection for adjuvant therapy and multimodality treatment. The aim of this study was to evaluate the impact of clinico-histological parameters on prognosis in node-negative rectal cancer patients. One hundred and thirty-nine consecutive node negative rectal cancer patients with complete five-year follow-up were studied prospectively. All of them underwent curative anterior resection with total mesorectal excision technique. Seventy-eight patients with tumour penetration beyond the bowel wall received neo-adjuvant short-course radiation (25 Gy) followed by surgery within 1 week and postoperative chemotherapy with 5-fluorouracil and folinic acid in six cycles or adjuvant radiochemotherapy: irradiation (50.4 Gy) combined with chemotherapy (as above). Cancer-specific survival was calculated according to the Kaplan-Meier method. Variables significant in univariate analysis by log-rank test (P < 0.05) entered the Cox proportional hazard model. Survival was decreased for males, older patients (>60 years) with extraperitoneal, poorly differentiated cancers, tumours with mucinous histology and with the absence of lymphocytic infiltration but with the lack of statistical importance. Prognosis was significantly improved for patients with T2 tumours versus T3 (P < 0.01) and with cancers with expanding growth comparing to diffusely infiltrating ones (P < 0.01). In multivariate analysis these parameters significantly and independently influenced survival (P < 0.01 and P < 0.05, respectively). Diffusely infiltrating growth of tumour can reflect the more aggressive cancer behaviour and unfavourable course of disease despite the optimised local control. Apart from the extent of tumour penetration the type of invasive margin can be an additional parameter helpful for the optimal treatment planning and better patient selection for postoperative chemotherapy.

[The significance of elastic staining in detecting vascular invasion in colorectal carcinoma]

Venous invasion (VI) is one of the most important prognostic factors in colorectal carcinomas (CRC). The interobserver variation of this feature varies between 10% and 89.5%, mainly due to the specimen processing and staining. VI was assessed using haematoxylin and eosin (H+E) alone in 611 cases and with elastic stain (orcein-haematoxylin) in 243 CRCs. The stage, the pattern of invasion and the presence of intramural and extramural VI were determined. VI was identified in 27.45% of the H+E stained sections and in 67.1% using elastic stain counterstained with haematoxylin. The incidence of VI proved stage dependent as it has been noted in 13% of Dukes A, 36% of Dukes B, 80% of Dukes C and in 83% of CRCs with distant metastasis. The pattern of invasion is strongly connected to the VI, accordingly, VI could be identified in 82% of CRCs with invasive and only in 44% with expansive margin. The use of elastic stain did not help in differentiation of extramural tumour deposits due to the damage of elastic membranes in the vascular walls and the presence of elastic fibres in the lymph node capsule. As a conclusion, the routine use of elastic stains in our practice doubled the identification of VI. The frequency of VI depends on the stage and pattern of invasion in CRCs. As it is more likely to occur in the advanced CRCs, the use of elastic stain is even more suggested in Dukes B carcinomas with invasive margin.

Preoperative staging and treatment options in T1 rectal adenocarcinoma

BACKGROUND

Major rectal resection for T1 rectal cancer offers more than 95% cancer specific five-year survival to patients surviving the first 30 days after surgery. A significant further improvement by development of the surgical technique may not be possible. Improvements in the total survival rate have to come from a more differentiated treatment modality, taking patient and procedure related risk factors into account. Subgroups of patients have operative mortality risks of 10% or more. Operative complications and long-term side effects after rectum resection are frequent and often severe.

RESULTS

Local treatment of T1 cancers combined with close follow-up, early salvage surgery or later radical resection of local recurrences or with chemo-radiation may lead to fewer severe complications and comparable, or even better, long-term survival. Accurate preoperative staging and careful selection of patients for local or non-operative treatment are mandatory. As preoperative staging, at present, is not sufficiently accurate, strategies for completion, salvage or rescue surgery is important, and must be accepted by the patient before local treatment for cure is initiated.

RECOMMENDATIONS

It is recommended that polyps with low-risk T1 cancers should be treated with endoscopic snare resection in case of Haggitt's stage 1 or 2. TEM is recommended if resection margins are uncertain after snare resection for Haggitt's stage 3 and 4, and for sessile and flat, low-risk T1 cancers. Average risk patients with high-risk T1 cancers should be offered rectum resection, but old and comorbid patients with high-risk T1 cancers should be treated individually according to objective criteria as age, physical performance as well as patient's preference. All patients treated for cure with local resection or non-surgical methods should be followed closely.