Shifting from clinical to biologic indicators of prognosis after resection of hepatic colorectal metastases

The impact of resection margin on overall survival for patients with colon cancer liver metastasis varied according to the primary cancer location

INTRODUCTION

Investigation into right and left-sided primary colon liver metastasis (CLM) has revealed differences in the tumor biology and prognosis. This indicates that preoperative and operative factors may affect outcomes of right-sided primary CLM differently than left. This retrospective analysis investigated the effects of resection margin stratified by left and right-sided primary CLM on overall survival (OS) for patients undergoing hepatectomy.

METHODS

A total of 732 patients undergoing hepatic resection for CLM at the Cleveland Clinic and Johns Hopkins were identified between 2002 and 2016. Clinically significant variables were analyzed using Cox proportional hazard regression. The cohort was then divided into patients with right and left-sided CLM and analyzed separately using Kaplan Meier analysis and Cox proportional hazard regression.

RESULTS

Cox proportional hazard regression showed that left-sided CLM with an R0 margin was a statistically significant predictor of OS even after controlling for other important factors (HR = 0.629, P = 0.024) but right-sided CLM with R0 margin was not (HR = 0.788, P = 0.245). Kaplan-Meier analysis demonstrated that patients with a left-sided CLM and R0 margin had the best prognosis (P = 0.037).

CONCLUSION

Surgical margin is an important prognostic factor for left-sided primary CLM but tumor biology may override surgical technique for right-sided CLM.

Clinical significance and prognostic relevance of KRAS, BRAF, PI3K and TP53 genetic mutation analysis for resectable and unresectable colorectal liver metastases: A systematic review of the current evidence

BACKGROUND

Hepatic resection is considered the optimal potentially curative treatment for colorectal liver metastases (CRLM). Following resection, up to two-thirds of patients will develop recurrence within 5-years. Genetic mutation analysis of CRLM, especially KRAS status, has been proposed as a means to guide treatment, as well as identifying patients who can derive the most survival benefit from hepatic resection.

METHODS

A systematic review of the literature was conducted the PubMed, Embase and Cochrane library through February 8th, 2018. The following algorithm was applied: "(colorectal OR rectal OR colon OR colonic) AND (liver OR hepatic) AND (metastasis OR metastases) AND (gene OR mutation OR KRAS OR BRAF OR SMAD4 OR RAS OR TP53 OR P53 OR APC OR PI3K OR MSI OR EGFR OR MACC1 OR microsatellite)."

RESULTS

From the 2404 records retrieved, 78 studies were finally deemed eligible; 47 studies reported mutational data on patients with resectable CRLM, whereas 31 studies reported on patients with unresectable CRLM. Mutational analyses were mostly performed on the CRLM specimen rather than the primary CRC. The vast majority of studies reported on the KRAS mutational status (88.5%, n = 69/78). Prevalence of KRAS mutations ranged from 25% to 52%. Most studies reported that RAS mutation was a negative prognostic factor for overall (OS) (n = 24) and recurrence-free (RFS) (n = 9) survival; a few reports noted no effect of RAS mutational status on OS (n = 4) or RFS (n = 6). Twelve studies reported on BRAF mutations with a prevalence of BRAF mutation ranging from 0 to 9.1% in resected CRLM specimens. BRAF mutation was strongly associated with a worse prognosis. TP53 and PIK3CA gene mutations did not affect long-term outcomes.

CONCLUSIONS

The biological status of each tumor provides the basis for individualized cancer therapeutics. Data on the mutational status on CRLM should be a part of multidisciplinary discussions to help inform the therapeutic approach, type of chemotherapy, as well as timing and approach of surgical resection.

The Tumor Burden Score: A New "Metro-ticket" Prognostic Tool For Colorectal Liver Metastases Based on Tumor Size and Number of Tumors

OBJECTIVE

To apply the principles of the Metro-ticket paradigm to develop a prognostic model for patients undergoing hepatic resection of colorectal liver metastasis (CRLM).

BACKGROUND

Whereas the hepatocellular "Metro-ticket" prognostic tool utilizes a continuum of tumor size and number, a similar concept of a CRLM Metro-ticket paradigm has not been investigated.

METHODS

Tumor Burden Score (TBS) was defined using distance from the origin on a Cartesian plane incorporating maximum tumor size (x-axis) and number of lesions (y-axis). The discriminatory power [area under the curve (AUC)] and goodness-of-fit (Akaike information criteria) of the TBS model versus standard tumor morphology categorization were assessed. The TBS model was validated using 2 external cohorts from Asia and Europe.

RESULTS

TBS (AUC 0.669) out-performed both maximum tumor size (AUC 0.619) and number of tumors (AUC 0.595) in predicting overall survival (OS) (P < 0.05). As TBS increased, survival incrementally worsened (5-year OS: zone 1, zone 2, and zone 3-68.9%, 49.4%, and 25.5%; P < 0.05). The stratification of survival based on traditional tumor size and number cut-off criteria was poor. Specifically, 5-year survival for patients in category 1, category 2, and category 3 was 58.3%, 45.5%, and 50.6%, respectively (P > 0.05). The corrected Akaike score information criteria value of the TBS model (2865) was lower than the traditional tumor morphologic categorization model (2905). Survival analysis revealed excellent prognostic discrimination for the TBS model among patients in both external cohorts (P< 0.05).

CONCLUSIONS

An externally validated "Metro-ticket" TBS model had excellent prognostic discriminatory power. TBS may be an accurate tool to account for the impact of tumor morphology on long-term survival among patients undergoing resection of CRLM.

Kras mutation is a marker of worse oncologic outcomes after percutaneous radiofrequency ablation of colorectal liver metastases

BACKGROUND

Kras mutation has been associated with shorter overall survival and time to disease recurrence after resection of colorectal liver metastases (CLM). This study evaluated the prognostic value of Kras mutation in patients with CLM treated by percutaneous radiofrequency ablation (RFA).

METHODS

This is an IRB waived retrospective analysis of the impact of KRAS mutation status on oncologic outcomes after CLM RFA. The endpoints were overall survival (OS), local tumor progression (LTP) rates, and incidence of new liver, lung, and peritoneal metastases. Survival times were calculated using Kaplan-Meier methodology from the time of RFA.

RESULTS

The study enrolled 97 patients. Kras exon 2 mutation was detected in 39% (38/97) of patients. On univariate analysis, Kras mutation (P=0.016) (HR: 1.8; 95% CI: 1.1 - 2.9) was a significant predictor of OS and retained significance on multivariate analysis. Kras mutation was a significant predictor of new liver metastases (P=0.037) (SHR: 2.0; CI: 1.0-3.7) and peritoneal metastases (P=0.015) (sHR: 3.0; 95% CI: 1.2-7.2) on multivariate analysis. Kras mutation was a significant predictor of LTP after RFA of CLM ablated with margins of 1-5 mm (P=0.018) (SHR: 3.0; 95% CI: 1.2-7.7) with an LTP rate of 80% (12/15) versus 41% (11/27) for wild type.

CONCLUSION

Kras mutation is a significant predictor of overall survival, new liver, and peritoneal metastases after RFA of CLM. A minimal radiographic ablation margin ≥ 6 mm is essential for local tumor control especially for mutant CLM.

The prognostic implications of primary colorectal tumor location on recurrence and overall survival in patients undergoing resection for colorectal liver metastasis

BACKGROUND AND OBJECTIVES

The prognostic impact of primary colorectal cancer (CRC) location following resection of colorectal liver metastasis (CRLM) remains largely unknown. We sought to characterize the prognostic implications of primary tumor location among patients who underwent curative-intent hepatectomy for CRLM.

METHODS

Tumors of the cecum, ascending, and transverse colon were defined as right-sided; tumors of the sigmoid flexure, descending, and sigmoid colon were defined as left-sided. Clinicopathologic and long-term survival data were collected and assessed using univariable and multivariable analyses.

RESULTS

About 475 patients who underwent CRLM resection at a single institution were included; most patients had left-sided tumors (n = 284). Median and 5-year RFS was 20.2 months and 28.0%, respectively. Patients who had a left-sided primary tumor had a shorter RFS compared with patients who had a right-sided tumor (P = 0.01). Although site of and time to recurrence did not differ between the two groups (P > 0.05), patients with right-sided primary tumors were more likely to recur with advanced disease (i.e., ≥4 recurrent lesions) (P < 0.01). In turn, patients with right-sided tumors had both worse OS (P = 0.03) and worse survival after recurrence (P = 0.01).

CONCLUSION

While patients with right-sided tumors experienced longer RFS, when these patients did recur following CRLM resection, disease extent was more advanced. In turn, OS following recurrence was shorter among patients with right-sided CRC. J. Surg. Oncol. 2016;114:803-809. © 2016 2016 Wiley Periodicals, Inc.

Pre-hepatectomy carcinoembryonic antigen (CEA) levels among patients undergoing resection of colorectal liver metastases: do CEA levels still have prognostic implications?

BACKGROUND

The impact of prehepatectomy carcinoembryonic antigen (CEA) levels in the era of modern chemotherapy and expanded surgical indications for colorectal liver metastasis (CRLM) remains not well defined.

METHODS

484 patients were identified and divided into two groups by surgical time period (group 1: 2000-2007 vs. group 2: 2008-2015). The prognostic significance of pre-hepatectomy CEA was determined by assessing the HRs associated with various cut-off levels ranging from 5 to 200 ng/mL.

RESULTS

Median CRLM number was comparable in both groups (group 1: 2 vs. group 2: 2, P = 0.504). Bilobar disease was more frequent in group 2 (30.1% vs. 42.5%, P = 0.006). The administration of modern chemotherapy and/or biologic agents increased over time (49.5% vs. 67.9%, P < 0.001). Preoperative CEA independently predicted OS in group 1, even with a cut-off as low as >5 ng/mL. However, in group 2 it predicted recurrence and survival only after exceeding 70 and 50 ng/mL, respectively. Of note, in group 2, CEA was strongly associated with survival when CEA levels exceeded 70 ng/mL (HR 4.84).

CONCLUSIONS

While pre-hepatectomy CEA level may still have prognostic utility in CRLM resection, the optimal cut-off value has increased in the era of modern chemotherapy.

Surgical options for initially unresectable colorectal liver metastases

Although the frontiers of liver resection for colorectal liver metastases have broadened in recent decades, approximately 75% of these patients present with unresectable metastases at the time of their diagnosis. In the past, these patients underwent only palliative treatment, without the chance of a cure. In the previous two decades, several therapeutic strategies have been developed that render resectable those metastases that were initially unresectable, thus offering the chance of long-term survival and even a cure to these patients. The oncosurgical modalities that are available include liver resection following portal vein ligation/embolization, “two-stage” liver resection, one-stage ultrasonically guided liver resection, hepatectomy following conversion chemotherapy, and liver resection combined with thermal ablation. Moreover, in recent years, certain authors have recommended the revisiting of the concept of liver transplantation in highly selected patients with unresectable colorectal liver metastases and favorable prognostic factors. By employing such therapies, the number of patients with colorectal liver metastases who undergo a potentially curative treatment could increase to 40%. The safety profile of these approaches is acceptable (morbidity rates as high as 45%, mortality rates of less than 5%). Furthermore, the 5-year survival rates (approximately 30%) are significantly increased over those that were achieved with palliative treatment.

Treating patients with colon cancer liver metastasis: a nationwide analysis of therapeutic decision making

BACKGROUND

Criteria for resectability of colon cancer liver metastases (CLM) are evolving, yet little is known about how physicians choose a therapeutic strategy for potentially resectable CLM.

METHODS

Physicians completed a national Web-based survey that consisted of varied CLM conjoint tasks. Respondents chose among three treatment strategies: immediate liver resection (LR), preoperative chemotherapy followed by surgery (C → LR), or palliative chemotherapy (PC). Data were analyzed by multinomial logistic regression, yielding odds ratios (OR).

RESULTS

Of 219 respondents, 79 % practiced at academic centers and 63 % were in practice ≥10 years. Median number of cases evaluated was four per month. Surgical training varied: 51 % surgical oncology, 44 % hepato-pancreato-biliary/transplantation, 5 % no fellowship. Although each factor affected the choice of CLM therapy, the relative effect differed. Hilar lymph node disease predicted a strong aversion to LR with surgeons more likely to choose C → LR (OR 8.92) or PC (OR 49.9). Solitary lung metastasis also deterred choice of LR, with respondents favoring C → LR (OR 4.43) or PC (OR 6.97). After controlling for clinical factors, surgeons with more years in practice were more likely to choose PC over C → LR (OR 1.94) (P = 0.005). Surgical oncology-trained surgeons were more likely than hepatobiliary/transplant-trained surgeons to choose C → LR (OR 2.53) or PC (OR 4.15) (P < 0.001).

CONCLUSIONS

This is the first nationwide study to define the relative impact of key clinical factors on choice of therapy for CLM. Although clinical factors influence choice of therapy, surgical subspeciality and physician experience are also important determinants of care.

Liver transplantation for colorectal liver metastases: revisiting the concept

Liver transplantation (Lt) for colorectal cancer (CRC) liver metastases is no more considered due to the poor outcome observed up to the 1990s. According to the European Liver Transplant Registry (ELTR), 1- and 5-year patient survival following Lt for CRC liver metastases performed prior to 1995 was 62% and 18%, respectively. However, 44% of graft loss or patient deaths were not related to tumor recurrence. Over the last 20 years there has been dramatic progress in patient survival after Lt, thus it could be anticipated that survival after Lt for CRC secondaries today would exceed from far, the outcome of the past experience. By utilizing new imaging techniques for proper patient selection, modern chemotherapy and aggressive multimodal treatment against metastases, long term survivors and even cure could be expected. Preliminary data from a pilot study show an overall survival rate of 94% after a median follow up of 25 months. While long term survival after the first Lt is 80% all indications confounded, 5-year survival after repeat Lt is no more than 50% to 55%. If patients transplanted for CRC secondaries can reach the latter survival rate, it could be difficult to discriminate them in the liver allocation system and live donation could be an option.

Defining patient outcomes in stage IV colorectal cancer: a prospective study with baseline stratification according to disease resectability status

Background:

Stage IV colorectal cancer encompasses a broad patient population in which both curative and palliative management strategies may be used. In a phase II study primarily designed to assess the efficacy of capecitabine and oxaliplatin, we were able to prospectively examine the outcomes of patients with stage IV colorectal cancer according to the baseline resectability status.

Methods:

At enrolment, patients were stratified into three subgroups according to the resectability of liver disease and treatment intent: palliative chemotherapy (subgroup A), conversion therapy (subgroup B) or neoadjuvant therapy (subgroup C). All patients received chemotherapy with capecitabine 2000 mg m^–2 on days 1–14 and oxaliplatin 130 mg m^–2 on day 1 repeated every 3 weeks. Imaging was repeated every four cycles where feasible liver resection was undertaken after four or eight cycles of chemotherapy.

Results:

Of 128 enrolled patients, 74, 22 and 32 were stratified into subgroups A, B and C, respectively. Attempt at curative liver resection was undertaken in 10 (45%) patients in subgroup B and 19 (59%) in subgroup C. The median overall survival was 14.6, 24.5 and 52.9 months in subgroups A, B and C, respectively. For patients in subgroups B and C who underwent an attempt at curative resection, 3-year progression-free survival was 10% in subgroup B and 37% for subgroup C.

Conclusions:

This prospective study shows the wide variation in outcome according to baseline resectability status and highlights the potential clinical value of a modified staging system to distinguish between these patient subgroups.

Echogenic appearance of colorectal liver metastases on intraoperative ultrasonography is associated with survival after hepatic resection

Survival after resection of colorectal liver metastases has traditionally been associated with clinicopathologic factors. We sought to investigate whether echogenicity of colorectal liver metastasis as assessed by intraoperative ultrasound (IOUS) was a prognostic factor after hepatic resection. Prospective data on tumor IOUS appearance were collected in 84 patients who underwent hepatic resection for colorectal liver metastasis. Images were digitally recorded, blindly reviewed, and scored for echogenicity (hypo-, iso-, or hyperechoic). The median tumor number was 1 and the median tumor size was 5.0 cm. At the time of surgery, the IOUS appearance of the colorectal liver metastases were hypoechoic in 35 (41.7%) patients, isoechoic in 37 (44.0%) patients, and hyperechoic in 12 (14.3%) patients. Traditional clinicopathologic prognostic factors were similarly distributed among the three echogenicity groups (all p > 0.05). Patients with a hypoechoic lesion had a significantly shorter median survival (30.2 months) compared with patients who had either an isoechoic (53.2 months) or hyperechoic (42.3 months) lesion (p = 0.005). The 5-year survival after hepatic resection of colorectal liver metastasis was also associated with the echogenic appearance of the lesion (hypoechoic 14.4 vs isoechoic 37.4 vs hyperechoic 46.2%) (p < 0.05). Intraoperative ultrasound echogenicity should be considered a prognostic factor after hepatic resection of metastatic colorectal cancer.