Value of tumor size as a prognostic variable in colorectal cancer: a critical reappraisal. Am J Clin Oncol. 2011;34:43-49. [PMID: 20101166 DOI: 10.1097/coc.0b013e3181cae8dd]

Evaluation of Extramural Venous Invasion by Diffusion-Weighted Magnetic Resonance Imaging and Computed Tomography in Rectal Adenocarcinoma

PURPOSE

The aim of this study is to evaluate the diagnostic contribution of diffusion-weighted magnetic resonance imaging (MRI) and computed tomography (CT) to distinguish extramural venous invasion (EMVI) in rectal adenocarcinoma.

MATERIALS AND METHODS

Fifty-eight patients who had been diagnosed with rectal adenocarcinoma (30 patients with EMVI and 28 patients without EMVI) were enrolled in the study. Apparent diffusion coefficient (ADC) values of the tumour and the EMVI (+) vein, the lengths of the tumours were measured on MRI. The diameters of the superior rectal vein (SRV)-inferior mesenteric vein (IMV) and distant metastatic spread were evaluated on CT. The ability of these findings to detect EMVI was assessed using receiver operating characteristic (ROC) analysis. Pathology was accepted as the reference test for EMVI.

RESULTS

Mean diameters of the SRV (4.9 ± 0.9 mm vs 3.7 ± 0.8 mm) and IMV (6.9 ± 0.8 mm vs 5.4 ± 0.9 mm) were significantly larger (P < .001) and tumour ADC values were significantly lower (0.926 ± 0.281 × 10^-3 mm²/s vs 1.026 ± 0.246 × 10^-3 mm²/s; P = .032) in EMVI (+) patients. Diameters of 3.95 mm for the SRV (area under the curve [AUC] ± standard error [SE]: 0.851 ± 0.051, P < .001, sensitivity: 93.3%, specificity: 67.9%) and 5.95 mm for the IMV (AUC ± SE: 0.893 ± 0.040, P < .001, sensitivity: 93.3%, specificity: 71.4%) and an ADC value of 0.929 × 10^-3 mm²/s (AUC ± SE: 0.664 ± 0.072, P = .032 sensitivity: 76.7%, specificity: 57.1%) were found to be cutoff values, determined by ROC analysis, for detection of EMVI. Distant metastases were significantly more prevalent in EMVI (+) patients (P < .001).

CONCLUSION

The measurement of ADC values and SRV-IMV diameters seems to have contribution for diagnosis of EMVI in rectal adenocarcinoma. EMVI (+) patients appear to have higher risks of distant metastases at diagnosis.

Comparison of different lymph node staging schemes in prostate cancer patients with lymph node metastasis

PURPOSE

In addition to standard TNM N staging, lymph node ratio (LNR) and log odds of metastatic lymph node (LODDS) staging methods have been developed for cancer staging. We compared the prognostic performance of the total number of lymph nodes examined (TNLE), number of metastatic lymph node (NMLN), LNR, and LODDS in prostate cancer.

METHODS

Data from 1400 patients diagnosed with prostate cancer between 2004 and 2009 who underwent lymphadenectomy were extracted from the Surveillance Epidemiology and End Results database. Kaplan-Meier methods and multivariable Cox regression analysis were used to evaluate the prognostic value of different lymph node staging schemes in patients with lymph node metastasis.

RESULTS

Univariate analysis showed that age, T stage, radiotherapy history, Gleason score, LNR classification, LODDS classification, and NMLN except TNLE classification were significant prognostic factors for overall survival. In multivariate analysis, LNR classification, LODDS classification, and NMLN but TNLE classification remained significant prognostic factors for overall survival. LNR classification had the highest C-index (0.672; 95% confidence interval [CI]: 0.609-0.734) and the lowest Akaike information criterion (AIC) (4057.018), indicating the best prognostic performance. Scatter plots showed that LODDS increased with increasing LNR, exhibiting a strong overall correlation between these two lymph node staging methods (r² = 0.9072). LNR and LODDS generally increased with increasing NMLN, although the correlation was relatively low.

CONCLUSION

Our results indicate that LNR and LODDS may be better predictors of overall survival than the AJCC/UICC N category in patients undergoing curative surgery for prostate cancer.

Adjuvant chemotherapy does not provide survival benefits to elderly patients with stage II colon cancer

To date, the effect of adjuvant chemotherapy after curative resection in patients with stage II colon cancer remains controversial. Still, little is known about the effects of adjuvant chemotherapy in patients with stage II colon cancer who are older than 70 years, as most studies did not focus on this population. This study aimed to investigate the oncologic outcomes of elderly patients with stage II colon cancer who underwent curative resection with or without postoperative adjuvant chemotherapy. We retrospectively reviewed medical records of patients older than 70 years who underwent curative resection of stage II primary colon cancer during 2002–2015. Patients were classified into surgery alone (SA) and adjuvant chemotherapy (AC) groups and propensity score-matched at a 1:1 ratio using a logistic regression. The end points were recurrence-free (RFS), cancer-specific (CSS) and overall survival (OS). Of the 623 patients who met the criteria, 145 were assigned to each arm after propensity score matching. The mean ages of the SA and AC groups were 74.3 and 74.0 years, respectively. A log-rank test revealed no significant inter-group differences in RFS (p = 0.202), CSS (p = 0.486) or OS (p = 0.299). In a Cox regression analysis, adjuvant chemotherapy was not found to be an independent factor affecting RFS (p = 0.206), CSS (p = 0.487) or OS (p = 0.301). Adjuvant chemotherapy does not appear to yield survival benefits in elderly patients with stage II colon cancer.

Simple Cholecystectomy Is Adequate for Patients With T1b Gallbladder Adenocarcinoma < 1 cm in Diameter

Purpose: Consensus-based clinical guidelines recommend that simple cholecystectomy (SC) is adequate for T1a gallbladder adenocarcinoma (GBA), but extended cholecystectomy (EC), SC plus lymphatic dissection, should be considered for T1b and more advanced GBA. Whether lymphatic dissection is necessary for the treatment of T1b GBA remains controversial. This study attempts to better define the current criteria for local treatment of T1b GBA, by examining the relationship between lymph node (LN) metastasis and tumor size in such patients.

Patients and methods: Clinical data from patients with T1b GBA receiving curative surgical treatment between 2004 and 2015 were collected from the Surveillance, Epidemiology, and End Results (SEER) database. Baseline characteristics for the entire cohort were described, and overall survival (OS) and cancer-specific survival (CSS) were analyzed with the Kaplan–Meier method.

Results: In total, 277 patients were enrolled for further analysis; 127 underwent lymphadenectomy. Among them, 23 patients had tumors <1 cm in diameter, none of which had LN metastasis; 104 patients had tumors ≥1 cm, 15 of which had positive LNs. In the group with tumor size <1 cm, there was no significant survival difference between treatment with SC or EC (P = 0.694). A clinical benefit was observed in T1b GBA patients with a tumor size ≥1 cm receiving EC vs. those receiving SC (P = 0.012).

Conclusion: SC was adequate for treatment of T1b GBA < 1 cm in diameter. This evidence may be included as part of current guidelines.

Value of tumor size as a prognostic factor in metastatic colorectal cancer patients after chemotherapy: a population-based study

Aim: To evaluate the relationship between tumor size and survival in metastatic colorectal cancer (mCRC) patients who received chemotherapy. Materials & methods: SEER database was accessed for eligible patients. Multivariate Cox regression analysis was performed to compare the effect of tumor size on overall survival (OS) and CRC-specific survival (CCSS). Results: Tumor size ≥5 cm was an independent risk factor for OS and CCSS in mCRC patients treated with chemotherapy. Tumor size <5 cm did not show a survival advantage in patients whose primary tumor site was rectosigmoid junction, while tumor size ≥5 cm was associated with poor OS and CCSS in left-and right-sided colorectal cancer. Conclusion: Tumor size ≥5 cm was associated with poor prognosis after receiving chemotherapy treatment and a risk factor for survival of mCRC.

Intraoperative Sentinel Node Mapping in the Colon: Potential and Pitfalls

Sentinel lymph node mapping (SLNM) may play a significant role in future delivery of colon cancer surgery because of an increase in early-stage, node-negative disease due to national bowel cancer screening programmes. Traditionally, colon lymphatic drainage has not been thought relevant as the operative approach cannot be tailored. Recent advances in local and endoscopic risk-reducing interventions for colonic malignancy have caused a rethink in approach. SLNM was initially attempted with blue dye techniques with limited success. Technological improvement has allowed surgeons to use near-infrared (NIR) light and NIR active tracers such as indocyanine green. This review provides an overview of the current status of intraoperative lymph node mapping in the colon, identifies challenges to the delivery of the techniques, and discusses potential solutions that may help SLNM play a role in improving the delivery of surgical care for patients with colon cancer.

Comparison of Different Lymph Node Staging Systems in Patients With Resectable Colorectal Cancer

Background and Objectives: Currently, the United States Joint Commission on Cancer (AJCC) N staging, lymph node positive rate (LNR), and log odds of positive lymph nodes (LODDS) are the main lymph node (LN) staging systems. However, the type of LN staging system that is more accurate in terms of prognostic performance remains controversial. We compared the prognostic accuracy of the three staging systems in patients with CRC and determine the best choice for clinical applications. Methods: From the Surveillance, Epidemiology, and End Results (SEER) database, 56,747 patients were identified who were diagnosed with CRC between 2004 and 2013. Akaike's Information Criterion (AIC) and Harrell's Consistency Index (c-index) were used to assess the relative discriminative abilities of different LN staging systems. Results: In 56,747 patients, when using classification cut-off values for evaluation, the LNR of Rosenberg et al. showed significantly better predictive power, especially when the number of dissected lymph nodes (NDLN) were insufficient. When analyzed as a continuous variable, the LODDS staging system performed the best and was not affected by the NDLN. Conclusions: We suggest that the LNR of Rosenberg et al. should be introduced into the AJCC system as a supplement when the NDLN is insufficient until the optimal LODDS cut-off values are calculated.

Evaluating the Effect of Lymph Node Status on Survival in Large Colon Cancer

Objective: This study aimed to investigate the effect of lymph node status on survival in large colon cancer. Methods: In the first cohort, patients diagnosed with non-metastatic colon cancer (N = 176,834) were identified from the Surveillance, Epidemiology, and End Results (SEER) database between January 1988 and December 2005. Further analyses were conducted in the other cohort (N = 855) from the Fudan University Shanghai Cancer Center (FUSCC) database. Results: In the SEER cohort, CSS differences increased as the tumor enlarged until a threshold tumor size group (tumor measuring 7-8 cm, P < 0.001) was reached, in which node positivity showed the maximum negative effect on CSS; multivariate Cox analyses showed that tumors measuring 7-8 cm presented a significant lower risk of cancer-specific mortality compared with those measuring 2-4 cm [hazard ratio (HR) = 1.087; 95% confidence interval (CI) = 1.014-1.165, P = 0.018]. In the FUSCC cohort, N0 tumors measuring 21-40 mm presented a higher risk of recurrence compared with those measuring 41-80 mm. Conclusions: Mortality risk of node positivity increased as tumor enlarged until a threshold tumor size (tumor size of 7-8 cm) was reached, mainly resulting from larger tumors without lymph node involvement being a surrogate for biologically indolent colon cancer of tumor recurrence. Our study could provide both researchers and clinicians a better understanding of colon cancer biology.

Polypectomy versus surgery in early colon cancer: size and location of colon cancer affect long-term survival

BACKGROUND AND AIMS

The colon cancer survival rate is significantly affected by location, stage, and size of the cancer. Polypectomy was shown be as equally effective as surgery in early-stage colon cancer, but there have been no established clinical guidelines in the management of colon cancer based on the size of the polyp or the tumor location. The aim of our study was to assess the early-stage colon cancer-specific survival rate in patients who underwent endoscopic polypectomy versus surgery, based on size and location of tumor in early-stage colon cancer.

METHODS

This is a population-based nationwide study in the USA.

RESULTS

Of 13,157 patients, 15.5% underwent endoscopic treatment and 84.5% underwent surgical therapy. For early cancer tumors located in the left colon, polypectomy yielded comparable 5-year survivals to surgery irrespective of size of the tumors. Five-year early cancer-specific survivals were similar for tumors located in the right colon that were < 20 mm in size (94.5 vs 94.3%, p value = 0.94). However, tumors > 20 mm in size that were located in the right colon had better survivals when treated surgically compared to those treated with polypectomy (20-39 mm: 91.8 vs 74.2%; ≥ 40 mm: 92.4 vs 60%, both p values < 0.01). Similar results were obtained on propensity score analysis.

CONCLUSIONS

Polypectomy was as effective as surgical therapy for small tumors. For larger tumors, surgical therapy is better than polypectomy for right-sided tumors, but both are equally effective for left-sided tumors.

Macroscopic serosal invasion and small tumor size as independent prognostic factors in stage IIA colon cancer

BACKGROUND

This study aimed to investigate the prognostic factors of patients with stage IIA (T3N0M0) colon cancer in terms of macroscopic serosal invasion and small tumor size.

METHODS

We enrolled 375 stage IIA colon cancer patients who underwent curative resection between January 2004 and December 2011. Macroscopic serosal invasion was defined as tumor nodules or colloid changes protruding the surface of the serosa. The clinicopathologic characteristics were analyzed to identify independent prognostic factors.

RESULTS

The median follow-up was 47 months (range, 1-90 months). On multivariate survival analysis, macroscopic serosal invasion (adjusted hazard ratio [HR] = 4.750; p = 0.013), tumor size < 5 cm (adjusted HR = 3.112, p = 0.009), perineural invasion (adjusted HR = 3.528; p = 0.002), < 12 retrieved lymph nodes (adjusted HR = 4.257; p = 0.002), and localized perforation (adjusted HR = 7.666; p = 0.008) were independent risk factors for recurrence.

CONCLUSION

We found novel prognostic factors of stage IIA colon cancer, including macroscopic serosal invasion and small tumor size (< 5 cm). Further studies are needed to evaluate the benefit of adjuvant chemotherapy in patients with these prognostic factors.

Real-world study of a novel prognostic scoring system: for a more precise prognostication and better clinical treatment guidance in stages II and III colon cancer

PURPOSE

This study aimed to improve the American Joint Committee on Cancer (AJCC) Tumor Node Metastases (TNM) staging system and demonstrate the improvement in prognostic accuracy and clinical management guidance in colon cancer using the novel prognostic score (P score).

METHODS

Eligible patients were identified using the Surveillance, Epidemiology, and End Results database. A P score (based on age, tumor size, and tumor grade) was assigned to each patient. The Cox proportional hazards regression analyses were performed to identify independent factors associated with prognosis. The Kaplan-Meier survival curves were used to analyze the prognosis of patients with colon cancer with different P scores. The TNM staging system was compared with the P score in stages I-IV by calculating the concordance index.

RESULTS

The multivariate Cox analysis indicated that a higher P score was independently associated with a higher risk of cancer-specific mortality. The Kaplan-Meier survival curves showed that the survival benefit gradually increased as the P score decreased. The concordance index rose from 0.5, 0.593, 0.633, and 0.551 of AJCC TNM staging system to 0.709, 0.651, 0.691, and 0.623 of P score in stages I-IV, respectively.

CONCLUSIONS

The P score was an independent prognostic factor of colon cancer and had a much better prognostic accuracy than the AJCC TNM staging system in all patients with colon cancer. It may help in identifying patients with high-risk stage II colon cancer who were candidates for adjuvant therapy and differentiating patients with stage III colon cancer for adjuvant therapy.

P-TNM staging system for colon cancer: combination of P-stage and AJCC TNM staging system for improving prognostic prediction and clinical management

AIM

This study focused on improving the American Joint Committee on Cancer TNM staging system and demonstrated an improvement in prognostic accuracy and clinical management of colon cancer using the P-TNM staging system.

PATIENTS AND METHODS

Eligible patients (N=56,800) were identified from the Surveillance, Epidemiology, and End Results database between January 1, 2010, and December 31, 2014. The P-stage (P0 or P1) was assigned to each patient based on age at diagnosis, tumor grade, and tumor size. The outcome of interest was cancer-specific survival (CSS). The Cox proportional hazards regression analyses were used to identify independent prognostic factors and analyze the CSS probabilities of patients with colon cancer having different P-TNM stages, respectively.

RESULTS

A total of 29,627 patients were assigned to P0-stage and 27,173 patients were assigned to P1-stage. The P1-stage was associated with a 98.1% increased risk of cancer-specific mortality (hazard ratio =1.981, 95% confidence interval =1.891-2.076, P<0.001), which was higher in patients with nonmetastatic colon cancer. The P1-stage patients had improvement in CSS compared with those in P0-stage in respective stages (P<0.001). Moreover, CSS decreased in stage I-P1 compared with stage IIA-P0 or IIIA-P0 (P<0.001), stage IIIA-P1 compared with stage IIA-P0 (P<0.001), stage IIB-P1 compared with stage IIIB-P0 or IIC-P0 (P<0.001), stage IIIB-P1 compared with stage IIC-P0 (P<0.001), and stage IIC-P1 compared with stage IIIC-P0 (P<0.001).

CONCLUSION

P-stage was an independent prognostic factor for colon cancer. This study strongly supported the incorporation of P-stage into the American Joint Committee on Cancer TNM staging system for a better approach to prognostication and, thus, more individualized risk-adaptive therapies in colon cancer.

Prognostic accuracy of different lymph node staging systems in rectal adenocarcinoma with or without preoperative radiation therapy

Background and objective

A variety of different lymph node (LN) staging systems have been developed to describe the lymph node status accurately. We aim to compare the prognostic accuracy of American Joint Committee on Cancer seventh N stage relative to negative number of lymph node (nLN), lymph node ratio (LNR) and log odds of metastatic lymph nodes (LODDS) in rectal adenocarcinoma (RC).

Methods

A total of 19 167 Stage II-III rectal cancer patients who underwent surgical resection of rectal adenocarcinoma were identified from Surveillance, Epidemiology and End Results database. Akaike's Information Criterion (AIC) and the Harrell's concordance index (c statistic) were used to evaluate the relative discriminative power of the different LN staging systems.

Results

Of the 19 167 patients, 10 958 received preoperative radiotherapy (pre-RT cohort) and 8209 patients were treated with surgical resection directly (SURG cohort). When assessed using categorical cutoff values, LNR has a somewhat better prognostic accuracy both in pre-RT (c-index: 0.62; AIC: 2988.6) and SURG groups (c-index: 0.60; AIC: 3359.8). Further analysis based on different total number of lymph node (TNLN) suggested that when less than 10 lymph nodes were retrieved, LNR exhibited significant superiority (pre-RT: c-index: 0.597, AIC: 1006.8; SURG: c-index: 0.560, AIC: 810.5). When analyzed as a continuous variable, the LODDS system performed the best and was not impacted by TNLN.

Conclusion

When assessed as a categorical variable, LNR was the most powerful method to predict survival for Stage II-III RC patients with limited TNLN. Rather, LODDS was the most accurate staging system regardless of the TNLN when LN status was modeled as continuous variable.

Magnetic resonance-based pelvimetry and tumor volumetry can predict surgical difficulty and oncologic outcome in locally advanced mid-low rectal cancer

PURPOSE

To investigate the impact of the pelvic dimensions and tumor volume on surgery in locally advanced rectal cancer.

METHODS

Patients who underwent open surgery after neoadjuvant long-course chemoradiation for primary rectal cancer were included. The predictive value of magnetic resonance-based pelvic measurements and tumor volume on the surgical difficulty and oncologic outcome were analyzed.

RESULTS

125 patients were included. The independent risk factors related to the circumferential resection margin status were the pT stage [odds ratio (OR) 3.64, confidence interval (CI) 1.409-7.327] and tumor volume after neoadjuvant chemoradiotherapy (OR 1.59, CI 1.018-2.767). The operative time (p = 0.014, OR 1.453) and pelvic depth (p = 0.023, OR 1.116) were independent predictive factors for anastomotic leak. The median follow-up was 72 (2-113) months. Local recurrence was seen in 17 (14.1%) patients. Anastomotic leak (OR 1.799, CI 0.978-3.277), the circumferential resection margin status (OR 3.217, CI 1.262-7.870) and the relative tumor volume rate (OR 1.260, CI 1.004-1.912) were independent prognosticators of local recurrence. The 5-year overall survival was 66.7%. The circumferential resection margin status (hazard ratio: 4.739, CI 2.276-9.317), pN stage (OR 3.267, CI 1.195-8.930) and relative tumor volume rate (OR 2.628, CI 1.042-6.631) were independent prognostic factors for the overall survival.

CONCLUSIONS

Relative dimensions of the tumor in the pelvis influence the local recurrence and overall survival rates. Magnetic resonance-based measurements can predict the difficulty of surgery and allow surgeons to consider the appropriate surgical approach.

Population-based screening improves histopathological prognostic factors in colorectal cancer

INTRODUCTION

Diagnosis of colorectal cancer (CRC) based on clinical symptoms is usually established in its advanced stages. One strategy for reducing mortality is the early detection and removal of preneoplastic and initial neoplastic lesions, even before the first symptoms appear, by means of population-based screening campaigns. The aim of the present study is to determine whether CRC diagnosed via a screening campaign has more favourable histopathological prognostic factors than when diagnosed in the symptomatic phase.

MATERIAL AND METHODS

The prospective study of all the patients undergoing programmed CRC surgery at the JM Morales Meseguer Hospital (Spain) is between 2004 and 2010. The patients were divided into two groups: one diagnosed from clinical symptoms and one through a screening campaign. The following factors were compared: tumour size; degree of tumour invasion of the wall; lymph node, perineural and lymphovascular involvement; tumour stage; and grade of differentiation.

RESULTS

Compared to the symptomatic group, the screen-detected patients had smaller-sized tumours (lesions of less than 5 cm in 84 vs 69.55%, p < 0.001), a lower degree of colorectal wall invasion (T0-1 in 36 vs 9.02%, p < 0.001), less lymph node involvement (N0 in 72 vs 58.76%, p > 0.05), less vascular invasion (7.20 vs 15.22%, p = 0.79) and less perineural invasion (6.4 vs 20.70%, p < 0.001). The TNM staging in the screening group was lower than in the symptomatic group (stage 0-1 in 50.40 vs 18.58%, p < 0.001).

CONCLUSIONS

CRC diagnosed through a population-based screening programme presents more favourable histopathological characteristics than that diagnosed from the appearance of symptoms.

Laparoscopic surgery for locally advanced T4 colon cancer: the long-term outcomes and prognostic factors

Purpose

For locally advanced pathological T4 (pT4) colon cancer, the safety and feasibility of laparoscopic procedures remain controversial. Therefore, this study aimed to assess short-term and long-term outcomes and to identify the prognostic factors in laparoscopic surgery for pT4 colon cancer.

Methods

The study group included 130 patients who underwent laparoscopic radical resection for pT4 colon and rectosigmoid cancer from January 2004 through December 2012. The short-term outcomes, long-term outcomes, and prognostic factors in pT4 colon cancer were analyzed.

Results

The median operative time was 205 min, with a median blood loss of 10 ml. The conversion rate was 3.8%, and 13 patients (10.0%) had postoperative complications. The radial resection margin was positive in 1 patient (0.8%). The median follow-up time was 73 months. The 5-year overall survival (OS) and recurrence-free survival (RFS) were 77.2 and 63.5%, respectively. On a multivariate analysis, a male sex [hazard ratio (HR) 3.09, p < 0.001], lymph node ratio ≥ 0.06 (HR 2.35, p = 0.021), tumor diameter < 38 mm (HR 2.57, p = 0.007), and right-sided colon cancer (HR 2.11, p = 0.047) were significantly related to a poor OS.

Conclusions

These results suggest that laparoscopic surgery for pT4 colon cancer is safe and feasible, and the oncological outcomes are acceptable. Based on the present findings, select patients with locally advanced colon cancer should not be excluded from laparoscopic surgery.

Prognostic value of tumor size in stage II and III colorectal cancer in Tunisian population

Aim: We aimed to identify a cutoff value of tumor size (TuS) correlated to prognosis of stage II and III colorectal cancer and to evaluate the prognostic significance. Patients & methods: We retrospectively analyzed 257 patients treated for stage II–III colorectal cancer between 2003 and 2014. We used receiver-operating characteristic to evaluate TuS performance accuracy to predict survival. We identified a cutoff value. We used the Kaplan–Meier method and Cox regression analysis to study survival and prognostic factors. Results: Area under the receiver-operating characteristic curve of TuS was 0.62 ± 0.048. A size of 4 cm was identified as a predictor of survival with a sensitivity of 88.2% and a specificity of 59.2%. We observed 98 patients with TuS ≤4 cm and 159 patients with TuS greater than 4 cm. Patients with TuS greater than 4 cm were more likely to have a cancer located in the colon (81.1 vs 70.4%, p = 0.002) and commonly pT4 (44 vs 22.4%, p = 0.0001). There was no difference in terms of gender, insufficient removed lymph nodes number, number of positive lymph nodes, stage and oxaliplatin administration between both groups. 5-year survival rate of patients with TuS ≥4 cm and TuS less than 4 cm was 76 and 84%, respectively (p = 0.008). Age ≥65 years, stage III, venous invasion and pN+ greater than 3 were significant bad prognostic factors in patients with TuS ≥4 cm in univariate analysis. Stage III was the only independent prognostic factor in multivariate analysis. Administration of chemotherapy was the only factor with significant impact on survival in univariate and multivariate analyses in patients with TuS less than 4 cm. Conclusion: TuS had not only an impact on survival but also interfered with other prognostic factors.

Does tumor size have its prognostic role in colorectal cancer? Re-evaluating its value in colorectal adenocarcinoma with different macroscopic growth pattern

BACKGROUND

Few previous studies have taken the growth pattern into consideration when analyzing the prognostic value of tumor size in colorectal cancer (CRC).

OBJECTIVE

We sought to reveal the prognostic role of tumor size in different macroscopic growth patterns of CRC.

MATERIALS AND METHODS

Using Cancer Center datasets, we identified 4057 cases with colorectal adenocarcinoma treated with curative resection. Macroscopic growth patterns of tumors were classified into three types: infiltrative, ulcerative and expansive types based on tumor gross appearance. Univariate and multivariate Cox regression analyses were performed to evaluate the prognostic factors for overall survival (OS) and disease-free survival (DFS).

RESULTS

In whole cohort, tumor size was an independent factor for OS (HR 1.10, 95%CI 1.04-1.16, p < 0.001). Subgroup analysis based on macroscopic growth pattern suggested that tumor size was an independent factor for OS both in the infiltrative (HR 1.37, 95%CI 1.12-1.66, p = 0.002) group and ulcerative group (HR 1.08, 95%CI 1.00-1.16, p = 0.044) and tumor size (HR 1.22, 95%CI 1.06-1.40, p = 0.004) was found as an independent factor for DFS only in infiltrative group.

CONCLUSIONS

Tumor size is an independent factor for OS and DFS in patients with colorectal adenocarcinoma of infiltrative type, while only for OS in patients of ulcerative type.

A critical reappraisal for the value of tumor size as a prognostic variable in rectal adenocarcinoma

Background and Objectives: To investigate critical prognostic factors for local recurrence in patients with rectal adenocarcinoma. Methods: We enrolled 221 consecutive patients who had histologically confirmed adenocarcinoma of the rectum and underwent surgery in our hospital between January 2000 and December 2014. Total mesorectal excision was performed in all patients undergoing a sphincter-sparing procedure or abdominal perineal resection of rectal cancer. To evaluate prognostic factors for local recurrence, we performed univariate and multivariate Cox regression analyses of the local recurrence rate in all patients. Overall survival rates were calculated using the Kaplan-Meier method, and Kaplan-Meier survival curves were compared using the log-rank test. Results: After the inclusion of only model variables of local recurrence with the highest or lowest univariate risk, a tumor size of <5 cm, a negative circumferential margin, well-to-moderately differentiated adenocarcinoma, low anterior resection, not receiving adjuvant RT, pathological T1-T3 stages, and upper- and middle-third rectal cancers were identified as strong prognostic factors with hazard ratios of 0.18, 0.20, 0.03, 0.01, 0.25, 0.18 and 0.18, respectively (95% confidence intervals [CIs], 0.06-0.58, 0.05-0.82, 0.03-0.38, 0.04-0.23, 0.05-0.64,0.09-0.70 and 0.06-0.54, respectively). After the multivariate Cox regression analysis of the local recurrence rate, a pathological tumor size of ≥5 cm was identified as the only prognostic risk factor (95% CI, 0.03-0.66; P = 0.013). The 5-year local recurrence rates among the patients having tumors measuring <5 cm and ≥5 cm in size were 1.40% and 23.00%, respectively (log-rank, P = 0.0001). The 5-year overall survival rates in the patients having tumors measuring <5 cm and ≥5 cm in size were 82.60% and 71.20%, respectively (log-rank, P = 0.001). Conclusion: A pathological tumor size of ≥5 cm is an independent prognostic factor for local recurrence in rectal adenocarcinoma.

Tumor size as a prognostic factor in patients with stage IIa colon cancer

BACKGROUND

The aim of this study was to identify stage II colon cancer patients with a high risk of recurrence.

METHODS

All patients who underwent surgery for stage II colon cancer (CC) were retrospectively enrolled and sub-grouped according to TNM staging (IIa-b-c) and stage IIa in high (IIaHR) and low risk (IIaLR) according to pathologic features. The primary outcomes measured were the 5-year overall survival (OS) and disease-free survival (DFS).

RESULTS

A total of 214 patients were reviewed. Only a maximum tumor diameter<4 cm in the IIaLR group was associated with a higher recurrence rate than a large tumor size (5-year DFS 71.7%vs.87.6%, p = 0.028). The DFS in the large IIaLR CC group was better than that in the IIaHR and IIb-c groups (5-year DFS: 92.7%vs.79.3%, p = 0.023). In contrast, the recurrence rate in the small IIaLR CC group was similar to that in the IIaHR, IIb-c stage CC group.

CONCLUSIONS

In stage IIa CC evaluation of the tumor size as a prognostic factor may help identify patients who could benefit from additional postoperative therapy.

An allometric pharmacokinetic/pharmacodynamics model for BI 893923, a novel IGF-1 receptor inhibitor

PURPOSE

BI 893923 is a novel IGF1R/INSR inhibitor with promising anti-tumor efficacy. Dose-limiting hyperglycemia has been observed for other IGF1R/INSR inhibitors in clinical trials. To counterbalance anti-tumor efficacy with the risk of hyperglycemia and to determine the therapeutic window, we aimed to develop a translational pharmacokinetic/pharmacodynamics model for BI 893923. This aimed to translate pharmacokinetics and pharmacodynamics from animals to humans by an allometrically scaled semi-mechanistic model.

METHODS

Model development was based on a previously published PK/PD model for BI 893923 in mice (Titze et al., Cancer Chemother Pharmacol 77:1303-1314, 13). PK and blood glucose parameters were scaled by allometric principles using body weight as a scaling factor along with an estimation of the parameter exponents. Biomarker and tumor growth parameters were extrapolated from mouse to human using the body weight ratio as scaling factor.

RESULTS

The allometric PK/PD model successfully described BI 893923 pharmacokinetics and blood glucose across mouse, rat, dog, minipig, and monkey. BI 893923 human exposure as well as blood glucose and tumor growth were predicted and compared for different dosing scenarios. A comprehensive risk-benefit analysis was conducted by determining the net clinical benefit for each schedule. An oral dose of 2750 mg BI 893923 divided in three evenly distributed doses was identified as the optimal human dosing regimen, predicting a tumor growth inhibition of 90.4% without associated hyperglycemia.

CONCLUSION

Our model supported human therapeutic dose estimation by rationalizing the optimal efficacious dosing regimen with minimal undesired effects. This modeling approach may be useful for PK/PD scaling of other IGF1R/INSR inhibitors.

LGR5 and CD133 as prognostic and predictive markers for fluoropyrimidine-based adjuvant chemotherapy in colorectal cancer

BACKGROUND

Expression of leucine-rich-repeat-containing G-protein-coupled receptor 5 (LGR5) gene is associated with a metastatic phenotype and poor prognosis in colorectal cancer (CRC). CD133 expression is a putative cancer stem cell marker and a proposed prognostic marker in CRC, whereas the predictive value of CD133 expression for effect of adjuvant chemotherapy in CRC is unclear.

MATERIAL AND METHODS

For the study of LGR5 mRNA and CD133 expression, tissue microarrays from 409 primary CRC stage II and III tumors, where patients had been randomized to adjuvant chemotherapy or surgery only, were available. LGR5 mRNA and CD133 expression were assessed by in situ hybridization (ISH) and immunohistochemistry (IHC), respectively. LGR5 mRNA and CD133 expression as prognostic and predictive markers were evaluated by univariate and multivariate analyses.

RESULTS

For all CRC patients, positive LGR5 mRNA and CD133 expression were associated with classic adenocarcinoma histology type (p = 0.001 and p = 0.014, respectively). Positive LGR5 mRNA expression was also associated with smaller tumor diameter for CRC stage II (p = 0.005), but not for CRC stage III (p = 0.054). For CRC stage II, lack of LGR5 mRNA expression was associated with longer time to recurrence (TTR) in Kaplan-Meier (p = 0.045) and in multivariate Cox analysis (HR 0.27, 95% CI 0.08-0.95, p = 0.041). For colon cancer stage III patients, lack of CD133 expression was associated with better effect of adjuvant chemotherapy (p = 0.016) in Kaplan-Meier univariate analysis, but the interaction between CD133 and adjuvant chemotherapy was not statistically significant in multivariate analysis (HR 0.59, 95% CI 0.18-1.89, p = 0.374).

CONCLUSION

LGR5 mRNA expression is a prognostic factor for CRC stage II patients, whereas the value of CD133 expression as prognostic and predictive biomarker is inconclusive.

Smaller tumor size is associated with poor survival in T4b colon cancer

AIM: To hypothesize that in patients with colon cancer showing heavy intestinal wall invasion without distant metastasis (T4bN0-2M0), small tumor size would correlate with more aggressive tumor behaviors and therefore poorer cancer-specific survival (CSS).

METHODS: We analyzed T4bN0-2M0 colon cancer patients in the Surveillance, Epidemiology and End Results (SEER) database. A preliminary analysis of T4bN0-2M0 colon cancer patients at the Fudan University Shanghai Cancer Center is also presented.

RESULTS: A total of 1734 T4bN0-2M0 colon cancer patients from the SEER database were included. Kaplan-Meier analysis revealed decreasing CSS with decreasing tumor size (P < 0.001). Subgroup analysis showed a significant association between poorer CSS with smaller tumor size in T4bN0 patients (P = 0.024), and a trend of association in T4bN1 (P = 0.182) and T4bN2 patients (P = 0.191). Multivariate analysis identified tumor size as an independent prognostic factor for CSS in T4bN0-2M0 patients (P = 0.024). Preliminary analysis of Fudan University Shanghai Cancer Center samples suggested the 5-year CSS was 50.0%, 72.9% and 77.1% in patients with tumors ≤ 4.0 cm, 4.0-7.0 cm and ≥ 7.0 cm.

CONCLUSION: Smaller tumor size is associated with poorer CSS in the T4bN0-2M0 subset of colon cancer, particularly in the T4bN0M0 subgroup.

Smaller tumor size is associated with poor survival in stage II colon cancer: An analysis of 7,719 patients in the SEER database

BACKGROUND

We hypothesized that in patients with colon cancer showing heavy intestinal wall invasion without lymph node metastasis (stage II), small tumor size would correlate with more aggressive tumor behaviors and thus poorer cancer-specific survival (CSS).

METHODS

We analyzed Caucasian patients with stage II colon cancer based on data from the US Surveillance, Epidemiology, and End Results (SEER) database. Survival was analyzed using the Kaplan-Meier method, and the log-rank test was used to identify differences. Risk factors were analyzed using the Cox proportional hazard model.

RESULTS

A total of 7719 stage II colon cancer patients from the SEER database were included in the analysis. The cutoff value (5.0 cm) was determined using the X-tile program. The Kaplan-Meier analysis showed that tumors <5.0 cm had a poorer CSS compared to tumors ≥5.0 cm (p = 0.006). Multivariate analysis indicated that tumor size is an independent prognostic factor for stage II patients, and compared to tumors <5.0 cm, tumors ≥5.0 cm were more likely to result in a better CSS (HR 0.775, 95% CI 0.691-0.870, p < 0.001). Tumor size was also analyzed as a continuous variable in the multivariate analysis, and the CSS decreased with decreasing tumor size (HR 0.958, 95% CI 0.936-0.981, p < 0.001). Subgroup analyses suggested that tumor size is also an independent prognostic factor for stage IIA (p = 0.002) and IIC (p < 0.001) patients.

CONCLUSIONS

Smaller tumor size is associated with poor CSS in the stage II colon cancer and particularly in the stage IIA and IIC subgroups.

Advanced imaging of colorectal cancer: From anatomy to molecular imaging

Imaging techniques play a key role in the management of patients with colorectal cancer. The introduction of new advanced anatomical, functional, and molecular imaging techniques may improve the assessment of diagnosis, prognosis, planning therapy, and assessment of response to treatment of these patients. Functional and molecular imaging techniques in clinical practice may allow the assessment of tumour-specific characteristics and tumour heterogeneity. This paper will review recent developments in imaging technologies and the evolving roles for these techniques in colorectal cancer.

TEACHING POINTS

• Imaging techniques play a key role in the management of patients with colorectal cancer. • Advanced imaging techniques improve the evaluation of these patients. • Functional and molecular imaging allows assessment of tumour hallmarks and tumour heterogeneity.

Serine protease inhibitor Kazal type 1 (SPINK1) as a prognostic marker in stage IV colon cancer patients receiving cetuximab based targeted therapy

BACKGROUND

Serine peptidase inhibitor Kazal type-1 (SPINK1), a trypsin kinase inhibitor, has well established associations with inflammation, cancer cell proliferation and carcinogenesis. However, the role of SPINK1 has not been investigated in stage IV colorectal cancer (CRC) patients receiving cetuximab based targeted therapy. The aim of this study was to evaluate the use of SPINK1 as a biomarker for predicting how patients with end stage CRC respond to anti-epidermal growth factor receptor (EGFR) therapies.

METHODS

Immunohistochemical staining was used for semiquantitative analysis of SPINK1 protein expression in 51 CRC cases. Expression of SPINK1 protein was then analysed to identify correlations with clinicopathological variables.

RESULTS

High SPINK1 expression was significantly associated with males (p=0.018). Kaplan-Meier analyses also showed that patients with high SPINK1 expression had significantly longer overall survival compared with controls (p=0.004). Multivariable analyses showed that SPINK1 expression and tumour size were significantly associated with prognosis (HR 0.416 and 0.437; 95% CI 0.217 to 0.797 and 0.236 to 0.810; p=0.008 and p=0.009, respectively) in these stage IV CRC cases.

CONCLUSIONS

High SPINK1 expression is associated with a good prognosis in stage IV CRC cases receiving cetuximab based targeted therapy. As SPINK1 expression is also an independent prognostic marker in these patients, it has potential use as a biomarker for clinical decision making and for designing personalised targeted therapies.

Association Between Very Small Tumor Size and Increased Cancer-Specific Mortality in Node-Positive Colon Cancer

BACKGROUND

Larger tumor size and lymph node involvement are traditionally associated with increased colon cancer-specific mortality.

OBJECTIVE

We sought to determine whether patients with very small tumors associated with lymph node involvement are at paradoxically increased risk of colon cancer-specific mortality in comparison with those who have larger tumors and lymph node involvement.

DESIGN

This is a retrospective cohort study using the Surveillance, Epidemiology, and End Results database.

SETTING

Geographic areas included in one of the 18 Surveillance, Epidemiology, and End Results registries were used.

PATIENTS

We identified 99,594 patients with nonmetastatic colon adenocarcinoma treated with surgery between 1988 and 2001.

MAIN OUTCOME MEASURES

The primary predictor variables were regional lymph node involvement and primary tumor size by longest dimension, grouped into the following predetermined strata: <5 mm, 5 to 19 mm, 20 to 39 mm, 40 to 59 mm, ≥ 60 mm. We used competing risks regression to determine differences in the risk of colon cancer-specific mortality between strata after controlling for T stage, tumor grade, age, year of diagnosis, race, and number of dissected lymph nodes.

RESULTS

Median follow-up among censored patients was 12.9 years. We found a significant interaction between lymph node involvement and tumor size (p < 0.05). Among those with node-negative disease, colon cancer-specific mortality increased monotonically with tumor size. In contrast, among those with node-positive disease, patients with the smallest tumors (<5 mm) were at increased risk of 10-year colon cancer-specific mortality compared with those with tumors sized 5 to 19 mm, 20 to 39 mm, 40 to 59 mm, and ≥60 mm (53.3% vs. 30.1%, 37.5%, 39.2%, and 39.7%; adjusted hazard ratios, 1.63-2.24; p < 0.05 in all cases).

LIMITATIONS

The main limitations are the retrospective design and information available in the study database.

CONCLUSION

In the setting of lymph node involvement, very small tumor size may predict for increased colon cancer-specific mortality compared with larger tumors. Smaller tumors associated with lymph node involvement may represent more aggressive malignancies with a distinct biology that merits further investigation.

The preoperative SUVmax for (18)F-FDG uptake predicts survival in patients with colorectal cancer

Background

The study was to investigate whether ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) uptake, analyzed by positron emission tomography (PET), can be used preoperatively to predict survival in Chinese patients with colorectal carcinoma.

Methods

A prospectively maintained colorectal cancer database was retrospectively reviewed between June 2009 and December 2011. All included patients had been newly diagnosed with colorectal cancer (of various stages) and evaluated by ¹⁸F-FDG-PET/computed tomography (CT) within the 2 weeks preceding surgery. Univariate and multivariate analyses were used to determine whether the maximal standardized uptake value (SUVmax) and various clinicopathological and immunohistochemical factors were correlated with survival. Receiver operating characteristics (ROC) curve and Kaplan-Meier survival curve analyses were used to explore whether SUVmax could predict survival in these patients.

Results

A total of 107 patients were enrolled in the study (mean age, 59.26 ± 12.66 years; 66.35 % males), with 77 surviving to the end of follow-up (average 60 months). Univariate analysis indicated that tumor size, TNM stage, nodal metastasis, the ratio of metastasized nodes to retrieved nodes, cyclin D1 immunostaining and SUVmax correlated with survival (P < 0.05). Multivariate analysis showed that only TNM stage and SUVmax were associated with survival (P < 0.05). ROC curve analysis determined the optimal SUVmax cutoff for predicting survival to be 11.85 (sensitivity, 73.3 %; specificity, 75.3 %). Survival was significantly longer in patients with preoperative SUVmax ≤11.85 (P < 0.001, log-rank test).

Conclusions

SUVmax, measured by ¹⁸F-FDG-PET/CT, provides a useful preoperative prognostic factor for patients with colorectal cancer.

Use of Preoperative MRI to Select Candidates for Local Excision of MRI-Staged T1 and T2 Rectal Cancer: Can MRI Select Patients With N0 Tumors?

BACKGROUND

To minimize the recurrence rate after local excision of rectal cancer, the false-negative rate of nodal staging should be minimized.

OBJECTIVE

The purpose of this study was to develop a set of criteria using preoperative MRI that would minimize the false-negative rate for the diagnosis of regional lymph node metastasis.

DESIGN

A prospectively maintained colorectal cancer database and MRI images were retrospectively reviewed.

SETTINGS

This study was conducted at a multidisciplinary tertiary center.

PATIENTS

A total of 246 consecutive patients who underwent MRI and curative-intent surgery for MRI-staged T1/T2 rectal cancer from January 2008 to July 2012 were included.

MAIN OUTCOME MEASURES

MRI features significantly associated with lymph node metastasis were identified using a χ test. Five diagnostic criteria for lymph node metastasis were created based on these predictive MRI features, and their false-negative rates were compared using the generalized estimating equation method.

RESULTS

Small size/homogeneity of lymph nodes and no visible tumor/partially involved muscular layer were significantly associated with lower risks of lymph node metastasis. When tumor invasion depth was not considered, the false-negative rate did not decrease below 10%, even when the strictest criterion for morphologic evaluation of lymph nodes (not visible or <3 mm) was used. Adding invasion depth to the diagnostic criteria significantly decreased the false-negative rate as low as 1.8%.

LIMITATIONS

This study is limited by its small sample size and retrospective nature.

CONCLUSIONS

Assessing both the depth of tumor invasion and lymph node morphology may reduce the false-negative rate and can be helpful to better identify candidates suitable for local excision of early stage rectal cancer. However, strict MRI criteria for oncologic safety might result in considerable false-positive cases and limit the application of local excision.

Distribution characteristics of 3,369 chinese colorectal cancer patients for gender, age, location and tumor size during colonoscopy

BACKGROUND

Studies have shown the existence of gender- and age-related differences in the incidence and anatomic distribution of colorectal cancers. The purposes of this study were to analyze the distribution characteristics of colorectal cancer patients regarding gender, age, location and tumor size in the course of colonoscopy.

MATERIALS AND METHODS

All colorectal cancer patients who underwent colonoscopy in the First Affiliated Hospital of Guangxi Medical University from 2003 to 2012 were included in our retrospective study. Demographic information (age and gender) and colonoscopy report information (tumor size and location) were collected and analyzed. To compare the gender differences in tumor location and tumor size, as well as the size differences in tumor location, the chi-square test was used.

RESULTS

A total of 3, 369 colorectal cancer patients (2, 007 men vs 1, 362 women) were included in our study. Statistical analysis showed there was no gender difference in the anatomic distribution of the tumors (p>0.05). However, there was a gender difference in tumor size (p>0.05). In addition, our study found there was a significant difference in tumor size between rectal and colon tumors (p>0.001).

CONCLUSIONS

There was no gender difference in the anatomic distribution of colorectal tumors. In addition, tumors observed in men were larger than in women.

A population-based study elicits a reverse correlation between age and overall survival in elderly patients with rectal carcinoma receiving adjuvant chemotherapy

Colorectal cancer is the third most common cancer and the fourth most common cause of cancer-related death globally. This population-based study aimed to explore the predictive factors that affected the overall survival of rectal cancer patients receiving adjuvant chemotherapy plus radical surgery using a Cox proportional hazards modeling approach. A total of 619 patients with rectal cancer who underwent surgery were enrolled between October 2006 and May 2013. Clinical characteristics of the patients were compared among the groups and potential prognostic factors were analyzed using the spss program, version 19.0. Patients aged ≥ 70 years have distinctive characteristics such as lager tumour size (≥ 5 cm), damaged micturition and higher incidence of diabetes compared to younger and middle-aged patients. Male gender, tumour size (≥ 5 cm), poor differentiation, later stage, adjuvant chemotherapy, damaged micturition, hypertension or diabetes are associated with a worse prognosis for rectal cancer patients (P < 0.05). However, smoking is a favourable factor to the patients (P = 0.018). Age of ≥ 70 years is an independent prognostic factor for patients with rectal cancer after surgery (P = 0.000) and elderly patients with Stage II and III disease receiving adjuvant chemotherapy show a favourable prognosis. The elderly patients who suffered from diabetes receiving adjuvant chemotherapy have a poor prognosis. Further prospective and large population studies are warranted to confirm the findings of this study.

Diagnostic relevance of overexpressed serine threonine tyrosine kinase/novel oncogene with kinase domain (STYK1/ NOK) mRNA in colorectal cancer

BACKGROUND

Alterations in gene expression levels or mutations of tyrosine kinases are detected in some human cancers. In this study, we examined whether serine threonine tyrosine kinase 1 (STYK1)/novel oncogene with kinase domain (NOK) is overexpressed in patients with colorectal cancer. We also examined the clinical relevance of STYK1/NOK expression in cancer tissues.

MATERIALS AND METHODS

In tumor samples of patients with colorectal cancer and their matched non-cancerous samples, STYK1/NOK messenger RNA (mRNA) expression was analyzed by quantitative reverse transcriptase polymerase chain reaction. Associations between the expression levels of STYK1/NOK and clinicopathological characteristics of colorectal cancer were also assessed using Mann-Whitney U and Kruskal-Wallis tests.

RESULTS

Upregulation of STYK1/NOK was found in cancer tissues even at early stage of colorectal cancer compared to normal adjacent tissues. The optimal cutoff point of 0.198 the STYK1/NOK expression showed 0.78 sensitivity and 0.75 specificity for diagnosis. Overexpressed STYK1/NOK was correlated with tumor size but had no association with other clinicopathological characteristics of colorectal cancer.

CONCLUSIONS

These results indicate that STYK1/NOK mRNA is widely expressed in the patients with colorectal cancer and suggest that inhibition of this molecule could potentially serve as a novel therapeutic target.

Soluble c-Met is a reliable and sensitive marker to detect c-Met expression level in lung cancer

c-Met has been demonstrated as an attractive target in lung cancer therapy. Current studies showed that detection of c-Met status in tumor is critical in Met-targeted therapy. However not all patients are suitable for tissue sample collection. It is important to discover novel surrogate markers to detect c-Met status. In the study, soluble c-Met (s-Met) in plasma from 146 Chinese lung cancer patients and 40 disease-free volunteers was measured by enzyme-linked immunosorbent. In parallel, expression of c-Met in those tumors was also assessed by immunohistochemistry. Results showed that, in 146 lung cancer patients, 93 were c-Met expression positive and 74 of 93 were overexpressed. In c-Met-overexpressed patients, plasma s-Met was significantly increased. And further studies showed that plasma s-Met linearly correlated with c-Met expression in tumor. After tumor was removed in Met-overexpressed patients via resection, plasma s-Met significantly decreased to basal level. In addition, plasma s-Met showed to be poorly correlated with tumor size in Met-overexpressed patients. These results demonstrated that plasma s-Met is a sensitive and reliable marker to detect c-Met overexpression in lung cancers, and it is independent of tumor volume.

Unfavorable effect of small tumor size on cause-specific survival in stage IIA colon cancer, a SEER-based study

BACKGROUND

We sought to determine the prognostic role of tumor size on cause-specific survival (CSS) of patients with stage IIA colon cancer.

METHODS

Surveillance, Epidemiology and End Results (SEER) database was utilized to identify patients with stage IIA colorectal cancer (examined lymph nodes ≥12) diagnosed from 1988 to 2003. The prognostic effect of tumor size on CSS was evaluated by univariate and multivariate analyses.

RESULTS

A total of 8775 patients were enrolled in the analysis. The median follow-up time was 109 months. As determined by minimal P value method, tumor sizes of 2.5 and 6.0 cm were used as optimal cutoff value to divide the cohort. The 8-year CSS of colon cancer with tumor sizes ≤2.5, 2.6-6.0, and >6.0 cm was 81.6, 86.2, and 86.7% respectively (P = 0.003). In the multivariate analysis of colon cancer, using ≤2.5-cm tumors as reference, decreased hazard ratio (HR) of CSS was observed in 2.6-6.0 cm (HR, 0.736; 95% confidence interval (CI), 0.599-0.905; P = 0.004) and >6.0 cm (HR, 0.770; 95% CI, 0.619-0.958; P = 0.019) tumors.

CONCLUSIONS

In stage IIA colon cancer, small tumor size represented a subset with decreased CSS. Further studies are merited to validate the unfavorable prognostic role of small tumor size in stage IIA colon cancer.

Tumor size predicts long-term survival in colon cancer: an analysis of the National Cancer Data Base

BACKGROUND

American Joint Committee on Cancer uses tumor size for "T" staging of many solid tumors for its effect on prognosis. However, tumor size has not been incorporated in tumor (T), nodal status (N), metastasis (M) staging for colon cancer. Hence, the National Cancer Data Base was used to determine whether tumor size correlates with TNM staging and survival.

METHODS

For the 300,386 patients, tumor size was divided into S1 (0 to 2 cm), S2 (>2 to 4 cm), S3 (>4 to 6 cm), and S4 (>6 cm). Statistical comparison was done for TNM stage, grade, and nodal status with tumor size. Kaplan-Meier survival analysis was done for each "S" stage.

RESULTS

Of the 300,386 patients, 13% were classified as S1, 39% S2, 30% S3 and 18% as S4. Right colon was the most common site (48%). Tumor size positively correlated with grade, T stage, and nodal stage. Tumor size was inversely associated with survival.

CONCLUSION

Tumor size is positively correlated with important prognostic factors and negatively impacted survival.

Can horizontal diameter of colorectal tumor help predict prognosis?

OBJECTIVE

We aimed to investigate the relationship between the horizontal tumor diameter and prognosis.

MATERIAL AND METHODS

Patients' records were analyzed retrospectively. Patient data, including age, gender, vertical penetration, anatomic location, differentiation of the tumor, tumor node metastasis (TNM) stage, survival rate, and disease-free survival, were analyzed to find out if there was any correlation with horizontal tumor diameter.

RESULTS

A total of 439 colorectal cancer patients were enrolled. Patients were stratified into two groups according to the horizontal tumor diameter (≤4.5 cm vs. >4.5 cm). Poorly differentiated tumors were significantly larger than other differentiation groups (p=0.003). The horizontal diameter increased with increase in T-stage (p<0.001). Similarly, the number of positive lymph nodes increased significantly as the size of the horizontal tumor diameter increased (p<0.001). The relationship between TNM staging and the horizontal diameter of tumors in both groups was examined, and it was found that the progression of tumor stage was accompanied by increased horizontal diameter (p<0.001). It was also found that the horizontal tumor diameter was not correlated with local recurrence (p=0.063). However, distant metastasis was higher in patients with a tumor larger than 4.5 cm (p=0.02). Although the disease-free survival was shorter in patients with a horizontal tumor diameter more than 4.5 cm, the difference was not statistically significant.

CONCLUSION

There is a significant relation between horizontal diameter of the tumor and depth of the tumor, lymph node involvement, overall survival, and distant metastasis. Horizontal diameter of the tumor can possibly be used as a prognostic factor in colorectal cancer patients.

Effect of bowel obstruction on stage IV colorectal cancer

Colorectal cancer (CRC) is the third most commonly diagnosed cancer worldwide, with a high mortality rate, particularly among patients with advanced-stage disease complicated by bowel obstruction. The present study aimed to investigate the value of different surgical procedures and potential predictors of survival for patients with stage IV CRC, with or without bowel obstruction. Between August, 1994 and December, 2005, a total of 2,950 CRC patients were diagnosed and treated at our hospital. Among these, 381 patients had stage IV disease and were divided into two groups according to the presence (n=295) or absence (n=86) of bowel obstruction. The clinical data of all the patients with stage IV CRC were retrospectively analyzed and all the patients were followed up. Our results demonstrated statistically significant differences in gender, radical resection, histological type, ascites, tumor location, peritoneal and liver metastases between the obstruction and non-obstruction groups. We also observed that hepatic metastases and radical resection were factors associated with prognosis according to the univariate and multivariate analyses. Furthermore, the mean/median survival time was 49.4/21.6 and 37.2/17.1 months in the non-obstruction and obstruction groups, respectively. In conclusion, obstruction was not found to be an independent indicator of survival for patients with stage IV CRC, with patients in the obstruction group exhibiting a worse overall survival compared to those in the non-obstruction group, whereas active radical surgery significantly improved the prognosis of patients with stage IV CRC.