Discrete improvement in racial disparity in survival among patients with stage IV colorectal cancer: a 21-year population-based analysis

Racial disparities in colorectal cancer clinicopathological and molecular tumor characteristics: a systematic review

PURPOSE

African Americans have the highest colorectal cancer (CRC) mortality of all racial groups in the USA, which may relate to differences in healthcare access or advanced stage at diagnosis. Recent evidence indicates that differences in tumor characteristics may also underlie disparities in mortality. To highlight recent findings and areas for investigation, we completed the first systematic review of racial disparities in CRC tumor prognostic markers, including clinicopathological markers, microsatellite instability (MSI), oncogene mutations, and novel markers, including cancer stem cells and immune markers.

METHODS

Relevant studies were identified via PubMed, limited to original research published within the last 10 years. Ninety-six articles were identified that compared the prevalence of mortality-related CRC tumor characteristics in African Americans (or other African ancestry populations) to White cases.

RESULTS

Tumors from African ancestry cases are approximately 10% more likely to contain mutations in KRAS, which confer elevated mortality and resistance to epidermal growth factor receptor inhibition. Conversely, African Americans have approximately 50% lower odds for BRAF-mutant tumors, which occur less frequently but have similar effects on mortality and therapeutic resistance. There is less consistent evidence supporting disparities in mutations for other oncogenes, including PIK3CA, TP53, APC, NRAS, HER2, and PTEN, although higher rates of PIK3CA mutations and lower prevalence of MSI status for African ancestry cases are supported by recent evidence. Although emerging evidence suggests that immune markers reflecting anti-tumor immunity in the tumor microenvironment may be lower for African American cases, there is insufficient evidence to evaluate disparities in other novel markers, cancer stem cells, microRNAs, and the consensus molecular subtypes.

CONCLUSION

Higher rates of KRAS-mutant tumors in in African Americans may contribute to disparities in CRC mortality. Additional work is required to understand whether emerging markers, including immune cells, underlie the elevated CRC mortality observed for African Americans.

Temporal development in survival, and gender and regional differences in the Swedish population of patients with synchronous and metachronous metastatic colorectal cancer

BACKGROUND

Survival in patients with metastatic colorectal cancer (mCRC) has markedly improved in patients included in clinical trials. In population-based materials, improvements were seen until about a decade ago, but it is unclear if survival has continued to improve. It is also unclear if regional or gender differences exist.

MATERIAL AND METHODS

All patients with mCRC (N = 19,566) in Sweden between 2007 and 2016 were identified from the national quality register, SCRCR, with almost complete coverage. Overall survival (OS) from diagnosis of metastatic disease was calculated in two calendar periods, 2007-2011 and 2012-2016. Differences between groups were compared using Cox regression.

RESULTS

Median age was 72 years, 55% were males, synchronous presentation was seen in 13,630 patients and metachronous in 5936. In synchronous disease, the primary tumour was removed more often during the first than the second period (51% vs 41%, p < 0.001). Median OS (mOS) was 14.0 months. It was longer in those with metachronous than synchronous disease (17.6 vs 13.1 months, p < 0.001) and in males (15.0 vs 12.8 months, p < 0.001), and markedly influenced by age and primary location. It was longer in patients diagnosed during the second period than during the first (14.9 vs 13.1 months, HR 0.89 (95% CI 0.86-0.92), p < 0.001). This difference was seen in all subgroups according to sex, age, presentation, and sidedness. mOS was about one month shorter in 1/6 healthcare regions, most pronounced during the first period. Differences in median of up to 5 months were seen between the region with the shortest and longest mOS.

CONCLUSIONS

Overall survival in Swedish patients with mCRC has improved during the past decade but is still substantially worse than reported from clinical trials/hospital-based series, reflecting the selection of patients to trials. Regional differences were seen, but they decreased with time. Women did not have a poorer prognosis in multivariable analyses.

Survival benefit of primary and metastatic tumor resection for colon cancer with liver metastases: A population based, propensity score-matched study

Background

Colon cancer remains one of the most common malignancies and we aimed to evaluate whether surgery has an effect on the survival of metastatic colon patients.

Methods

We analyzed 7,583 metastatic colon patients from the Surveillance, Epidemiology, between January 2010 and December 2015. Using Cox proportional hazards models and Kaplan-Meier curves, the overall survival rate (OS) and cancer-specific survival rate and End Results (SEER) registry (CSS) months (m) were evaluated with corresponding 95% confidence intervals (95% CIs). Propensity score matching (PSM) was performed to adjust for potential baseline confounding of all comparison groups.

Results

In general, receiving both primary and metastatic tumor resection (PMTR) remarkably improved OS and CSS compared with only primary tumor resection (PTR) after PS matching (PSM) (P < 0.05), with a significantly improved OS (HR = 0.74, 95%CI = 0.69–0.80) and CSS (HR = 0.71, 95%CI = 0.66–0.76) in all stage M1 colon patients. The stratification analysis indicated a significant difference between OS and CSS in M1a and M1b stages. After PSM, PMTR was found to be associated with remarkably improved OS and CSS for patients with liver metastases but not associated with OS and CSS of patients with lung metastases in both M1a and M1b stage.

Conclusions

The results from this large SEER cohort supported PMTR might improve the survival of colon patients with liver metastases on the basis of chemotherapy.

The association of health insurance and race with treatment and survival in patients with metastatic colorectal cancer

Background

Black patients and underinsured patients with colorectal cancer (CRC) present with more advanced disease and experience worse outcomes. The study aim was to evaluate the interaction of health insurance status and race with treatment and survival in metastatic CRC.

Materials and methods

Patients diagnosed with metastatic CRC within NCDB from 2006–2016 were included. Primary outcomes included receipt of chemotherapy and 3-year all-cause mortality. Multivariable logistic regression and Cox-regression (MVR) including a two-way interaction term of race and insurance were performed to evaluate the differential association of race and insurance with receipt of chemotherapy and mortality, respectively.

Results

128,031 patients were identified; 70.6% White, 14.4% Black, 5.7% Hispanic, and 9.3% Other race. Chemotherapy use was higher among White compared to Black patients. 3-year mortality rate was higher for Blacks and lower for Hispanics, in comparison with White patients. By MVR, Black patients were less likely to receive chemotherapy. When stratified by insurance status, Black patients with private and Medicare insurance were less likely to receive chemotherapy than White patients. All-cause mortality was higher in Black patients and lower in Hispanic patients, and these differences persisted after controlling for insurance and receipt of chemotherapy.

Conclusion

Black patients and uninsured or under-insured patients with metastatic CRC are less likely to receive chemotherapy and have increased mortality. The effect of health insurance among Blacks and Whites differs, however, and improving insurance alone does not appear to fully mitigate racial disparities in treatment and outcomes.

Network Pharmacology Analysis to Explore the Pharmacological Mechanism of Effective Chinese Medicines in Treating Metastatic Colorectal Cancer using Meta-Analysis Approach

The role of traditional Chinese medicine (TCM) on treatment of metastatic colorectal cancer (mCRC) remains controversial, and its active components and potential targets are still unclear. This study mainly aimed to assess the efficacy and safety of TCM in mCRC treatment through meta-analysis and explore the effective components and potential targets based on the network pharmacology method. We systematically searched PubMed, EMBASE, Cochrane, CBM, WanFang, and CNKI database for randomized controlled trials (RCTs) comparing the treatment of mCRC patients with and without TCM. A meta-analysis using RevMan 5.4 was conducted. In total, 25 clinical trials were analyzed, and the result demonstrated that TCM was closely correlated with the improved OS (HR: 0.63; 95% CI: 0.52-0.76; [Formula: see text] < 0.00001) and PFS (HR: 0.73; 95% CI: 0.61-0.88; [Formula: see text] = 0.0010). Then, high-frequency Chinese herbs from the prescriptions extracted from the trails included in the OS meta-analysis were counted to construct a core-effective prescription. The TCMSP database was used to retrieve the active chemical components and predict herb targets. The Genecards, OMIM, Disgenet, DrugBank, and TTD database were searched for colorectal cancer targets. R-package was used to construct the Component-Target (C-T) network based on the intersection genes. Further, we extracted hub genes from C-T network and performed functional enrichment and pathway analysis. Finally, the C-T network showed 120 herb and disease co-target genes, and the most important top 10 active components were: Quercetin, Luteolin, Wogonin, Kaempferol, Nobiletin, Baicalein, Licochalcone A, Naringenin, Isorhamnetin, and Acacetin. The first 20 hub genes were extracted: CDKN1A, CDK1, CDK2, E2F1, CDK4, PCNA, RB1, CCNA2, MAPK3, CCND1, CCNB1, JUN, MAPK1, RELA, FOS, MAPK8, STAT3, MAPK14, NR3C1, and MYC. Thus, effective Chinese herb components may inhibit the mCRC by targeting multiple biological processes of the above hub genes.

Midlife brain metastases in the United States: Is male at risk?

Background

Population‐based estimates of the impact of gender throughout the whole course of brain metastases (BMs) at the time of diagnosis of systemic malignancies are insufficient. We aimed to discover the influence of gender on the presence of BMs in newly diagnosed malignancies and the survival of those patients on a population‐based level.

Methods

Midlife patients (40 years ≤ age ≤60 years) with newly diagnosed malignancies and BMs at the time of diagnosis were abstracted from the Surveillance, Epidemiology, and End Results (SEER) database of the National Cancer Institute. Clinical variables adjusted patient data. The LASSO regression was performed to exclude the possibility of collinearity. Univariable and multivariable logistic regression analyses were applied to find independent predictors for the presence of BMs, while univariable and multivariable Cox proportional hazard regression analyses were used to determine prognosticators of survival. K‐M curves were used to perform the survival analysis.

Result

276,327 population‐based samples met inclusion criteria between 2014 and 2016, and 5747 (2.08%) patients were diagnosed with BMs at the time of diagnosis of systematic malignancies. Among all midlife patients with cancer, 44.02% (121,634) were male, while 51.68% (2970) were male among patients with BMs at the time of diagnosis. The most frequent tumor type was breast cancer (23.11%), and lung cancer had the highest incidence proportion of BMs among the entire cohort (19.34%). The multivariable logistic regression model suggested that female (vs. male, odds ratio [OR] 1.07, 95% CI: 1.01–1.14, p < 0.001) was associated with a higher risk of the presence of BMs at the time of diagnosis. Moreover, in the multivariable Cox model for all‐cause mortality in individuals with BMs at diagnosis, female (vs. male, hazard ratio [HR], 0.86, 95% CI, 0.80–0.92, p < 0.001) was shown to have a lower risk of decreased all‐cause mortality.

Conclusion

The middle‐aged females were at increased risk of developing BMs, while the middle‐aged males with BMs were at higher risk of having poorer survival.

Efficacy of Quxie Capsule in Metastatic Colorectal Cancer: Long-Term Survival Update of A Double-Blind, Randomized, Placebo Controlled Trial

OBJECTIVE

To verify the efficacy of Quxie Capsule in patients with metastatic colorectal cancer (mCRC).

METHODS

It was a block randomized, double-blind, placebo-controlled trial. Sixty patients with mCRC were randomized into 2 groups at a 1:1 ratio. The patients in the treatment group received conventional therapy including chemotherapy, radiotherapy, targeted therapy and supportive care, and Chinese herbal medicine combined with Quxie Capsule (each capsule of 0.4 g was orally administered at 50 mg/kg, twice daily, day 1-20, in a 30-day course) for 3 months. The patients in the control group received conventional therapy and Chinese herbal medicine combined with placebo for 3 months. Main outcome measures were overall survival (OS) and progression-free survival (PFS). Subgroup analysis was performed according to therapy lines, right or left-sided colon, targeted therapy and RAS gene status to determine the differences in PFS and OS between the two groups. Patients were followed up every 3 months until December 31st, 2018.

RESULTS

Median follow-up time was 19.4 months. The median OS was 23.9 months in the treatment group [95% confidence interval (CI) 15.9-28.5] vs. 14.3 months in the control group (95% CI 11.3-21.4, P<;0.05). Hazard ratio (95% CI) was 0.55 (0.31-0.95, P=0.040). There were no significant differences between the two groups in PFS (P>0.05). In the subgroups of ⩾second-line therapy, non-targeted therapy, RAS gene wild type and left-sided colon, the treatment group showed a significant survival benefit compared with the control group (P<;0.05 or P<;0.01), respectively.

CONCLUSION

Quxie Capsule can reduce the risk of death and prolong the OS of patients with mCRC. (Registration No. ChiCTR-IOR-16009733).

Impact of affordable care act on the treatment and outcomes for stage-IV colorectal cancer

BACKGROUND

Patients with advanced cancers are among the most vulnerable group of patients. We sought to analyze the impact of Affordable Care Act (ACA) on the interaction of socioeconomic factors with treatment and survival in patients with metastatic colorectal cancers.

METHODS

National Cancer Database (NCDB) was queried for patients with Stage-IV colon(CCa) and rectal cancers(R-Ca) diagnosed 2004-2015 and excluded those who did not receive any therapies within 6 months of diagnosis. Enrollment-rates were calculated as receipt of primary therapy as the incident-event (numerator) over time-to-initiation of therapy (denominator) and used to calculate incident-rate ratios that was analyzed using Poisson regression analysis- reported as enrollment-rate ratios (ER, <1 indicating lower enrollment rate). Multivariate Cox-proportional hazard model was performed for survival analysis and reported as calculate Hazard Ratios (HR).

RESULTS

For CCa, enrollment to primary therapies was significantly associated (p-value < 0.05) with gender, race, insurance status, educational status and treatment facility. The HR for non-Hispanic Blacks (NHB) vs. Whites (NHW) improved from 1.1(1.03-1.11),p-value<0.005 to no-significant difference post-ACA. For R-Ca, the enrollment rates were favorable for NHB vs. NHW and ER improved from 1.15(1.0-1.32),p-value = 0.054) to 1.29(1.06-1.58),p-value = 0.013 post-ACA. Despite this, the HR for mortality were unfavorable - 1.19(1.06-1.33),p-value = 0.003 that persisted through the post-ACA period. The HR was favorable for the insured group in both cancer groups (0.84 for R-Ca,0.86 for CCa) and for high-income vs. low-income group-0.90(0.87-0.94),p-value < 0.005 in CCa.

CONCLUSION

The ACA appears to have had a positive impact overall but further research and ongoing interventions are warranted to mitigate disparities in this population.

Informing metastatic colorectal cancer patients by quantifying multiple scenarios for survival time based on real-life data

Reported median overall survival (mOS) in metastatic colorectal cancer (mCRC) patients participating in systemic therapy trials has increased to over 30 months. It is uncertain whether trial results translate to real-life populations. Moreover, patients prefer presentation of multiple survival scenarios. Population-based data of all stage IV CRC patients diagnosed between 2008 and 2016 were obtained from the Netherlands Cancer Registry, which has a case ascertainment completeness surpassing 95%. We calculated the following percentiles (scenarios) of OS per year of diagnosis for the total population, and for treatment subgroups: 10th (best-case), 25th (upper-typical), 50th (median), 75th (lower-typical) and 90th (worst-case). Twenty-five percent of patients did not receive any antitumor treatment. From 2008 to 2016, mOS of the total population (n = 27275) remained unchanged at approximately 12 months. OS improved only for the upper-typical and best-case patients; by 4.2 to 29.1 months (P < .001), and by 6 to 62 months (P < .001), respectively. No clinically relevant change was observed among patients who received systemic therapy, with mOS close to 15 months and best-case scenario approximately 40 months. A clinically relevant improvement in survival over time was observed in patients who initially received metastasectomy and/or HIPEC only. In contrast to the wide belief based on trial data that mOS of mCRC patients receiving systemic therapy has improved substantially, improvement could not be demonstrated in our real-life population. Clinicians should consider quoting multiple survival scenarios based on real-life data instead of point estimates from clinical trials, when informing patients about their life expectancy.

Effect of Chinese Herbal Medicine on the Survival of Colorectal Cancer Patients With Liver-Limited Metastases: A Retrospective Cohort Study, 2008 to 2017

Background: Colorectal cancer (CRC) remains one of the leading contributors to cancer-related mortality and morbidity worldwide. Traditional Chinese medicines have been widely employed to treat various types of cancer in China. This investigation aims to determine the association between Chinese herbal medicine (CHM) therapy and survival outcomes in CRC patients with liver-limited metastases. Methods: A retrospective cohort study was performed among patients with colorectal liver metastases at the First Affiliated Hospital of Guangzhou University of Chinese Medicine in Guangzhou, China. Data from a series of consecutive patients were collected via an electronic medical record system or telephone follow-up. We defined high exposure as a period of CHM therapy lasting more than 6 months. The primary outcome was overall survival. Results: The study included the data of 191 patients from January 2008 to December 2017; 126 patients (65.97%) met the inclusion criteria of high exposure to CHM. Multivariate analyses revealed that high exposure to CHM was associated with better overall survival (hazard ratio = 0.444, 95% confidence interval = [0.213, 0.926], P = .030). The association was further confirmed by a subgroup exploratory analysis. Conclusion: Long-term CHM therapy is correlated with improved survival outcomes in CRC patients with liver-limited metastases.

Facilities that service economically advantaged neighborhoods perform surgical metastasectomy more often for patients with colorectal liver metastases

BACKGROUND

Metastasectomy of isolated colorectal liver metastases (CRLM) requires significant clinical expertise and may not be readily available or offered. The authors hypothesized that hospitals that treat a greater percentage of patients from higher income catchment areas are more likely to perform metastasectomies regardless of patient or tumor characteristics.

METHODS

Using the National Cancer Data Base, the authors classified facilities into facility income quartiles (FIQs) based on the percentage of patients from the wealthiest neighborhoods (by zip code). Quartile 1 included facilities with <2.1% of the patients residing within the highest income zip codes, quartile 2 included facilities with 2.2% to 15.6% of patients residing within the highest income zip codes, quartile 3 included facilities with 15.7% to 40.2% of patients residing within the highest income zip codes, and quartile 4 included facilities with 40.3% to 90.5% of patients residing within the highest income ZIP codes. Patient, tumor, and facility characteristics were analyzed using a multivariate logistic regression to identify associations between metastasectomy and FIQ.

RESULTS

Patients with CRLM were more likely to undergo metastasectomy at facilities in the highest FIQ compared with the lowest FIQ (18% vs 11% in FIQ4; P = .001). This trend was not observed in the resection of primary tumors for nonmetastatic CRLM (rates of 95% vs 93%; P = .94). After adjusting for individual insurance status, distance traveled, zip code-level individual income, tumor, and host, patients who were treated at the highest FIQ facilities were found to be more likely to undergo metastasectomy (odds ratio, 1.29; 95% CI, 1.02-1.72 [P = .03]).

CONCLUSIONS

Metastasectomy for CRLM is more likely to occur at facilities that serve a greater percentage of patients from high-income catchment areas, regardless of individual patient characteristics. This disparity uniquely affects those patients with advanced cancers for which specialized expertise for therapy is necessary.

Cohort Study on Prognosis of Patients with Metastatic Colorectal Cancer Treated with Integrated Chinese and Western Medicine

OBJECTIVE

To investigate the efficacy of integrated Chinese and Western medicine (IM) in the treatment of metastatic colorectal cancer (mCRC) in a cohort study.

METHODS

The survival outcome of patients receiving IM was compared with that of patients receiving Western medicine alone. The study design was adopted with "continuous administration of Chinese medicine for ⩾ 3 months" as the exposure factor. Patients who met this exposure factor were assigned to the IM cohort (Group A, 110 patients). Patients who did not meet this exposure factor were assigned to the Western medicine cohort (Group B, 225 patients). The overall survival (OS), progression-free survival (PFS), and 1st year, 2nd year, and 3rd year survival in the two cohorts were compared.

RESULTS

The median OS in Group A and B were 18 months [95% confidence interval (CI) 15-21] and 16 months (95% CI 14-18), respectively, and the median PFS in Group A and B were 6 months (95% CI 4-7) and 5 months (95% CI 4-6), respectively. No statistically significant differences were observed between the groups (P=0.186, P=0.223). Group A demonstrated significantly longer OS and PFS than Group B in the following subgroups: female patients, patients with lesions in the right half of the colon, and those who received first-line treatment (P<0.05). In the subgroup of elderly patients (age>65 years), the OS in Group A was longer than that in Group B (P<0.05).

CONCLUSION

IM could prolong the survival of patients with mCRC. (Registry No. ChiCTR-IOR-17010497).

Insurance Status, Not Race, is Associated With Use of Minimally Invasive Surgical Approach for Rectal Cancer

OBJECTIVE

To determine the impact of race and insurance on use of minimally invasive (MIS) compared with open techniques for rectal cancer in the United States.

BACKGROUND

Race and socioeconomic status have been implicated in disparities of rectal cancer treatment.

METHODS

Adults undergoing MIS (laparoscopic or robotic) or open rectal resections for stage I to III rectal adenocarcinoma were included from the National Cancer Database (2010-2012). Multivariate analyses were employed to examine the adjusted association of race and insurance with use of MIS versus open surgery.

RESULTS

Among 23,274 patients, 39% underwent MIS and 61% open surgery. Overall, 86% were white, 8% black, and 3% Asian. Factors associated with use of open versus MIS were black race, Medicare/Medicaid insurance, and lack of insurance. However, after adjustment for patient demographic, clinical, and treatment characteristics, black race was not associated with use of MIS versus open surgery [odds ratio [OR] 0.90, P = 0.07). Compared with privately insured patients, uninsured patients (OR 0.52, P < 0.01) and those with Medicare/Medicaid (OR 0.79, P < 0.01) were less likely to receive minimally invasive resections. Lack of insurance was significantly associated with less use of MIS in black (OR 0.59, P = 0.02) or white patients (OR 0.51, P < 0.01). However, among uninsured patients, black race was not associated with lower use of MIS (OR 0.96, P = 0.59).

CONCLUSIONS

Insurance status, not race, is associated with utilization of minimally invasive techniques for oncologic rectal resections. Due to the short-term benefits and cost-effectiveness of minimally invasive techniques, hospitals may need to improve access to these techniques, especially for uninsured patients.

Disparities by Race, Age, and Sex in the Improvement of Survival for Major Cancers: Results From the National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) Program in the United States, 1990 to 2010

IMPORTANCE

Substantial progress has been made in cancer diagnosis and treatment, resulting in a steady improvement in cancer survival. The degree of improvement by age, race, and sex remains unclear.

OBJECTIVE

To quantify the degree of survival improvement over time by age, race, and sex in the United States.

DESIGN, SETTING, AND PARTICIPANTS

Longitudinal analyses of cancer follow-up data from 1990 to 2010, from 1.02 million patients who had been diagnosed as having cancer of the colon or rectum, breast, prostate, lung, liver, pancreas, or ovary from 1990 to 2009 and who were included in 1 of 9 population-based registries of the National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) program.

MAIN OUTCOMES AND MEASURES

Hazard ratios (HRs) and 95% CIs for cancer-specific death were estimated for patients diagnosed as having any of these cancers during 1995 to 1999, 2000 to 2004, and 2005 to 2009, compared with those diagnosed in 1990 to 1994.

RESULTS

Significant improvements in survival were found for cancers of the colon or rectum, breast, prostate, lung, and liver. Improvements were more pronounced for younger patients. For patients aged 50 to 64 years and diagnosed from 2005 to 2009, adjusted HRs (95% CIs) were 0.57 (95% CI, 0.55-0.60), 0.48 (95% CI, 0.45-0.51), 0.61 (95% CI, 0.57-0.69), and 0.32 (95% CI, 0.30-0.36), for cancer of the colon or rectum, breast, liver, and prostate, respectively, compared with the same age groups of patients diagnosed during 1990 to 1994. However, the corresponding HRs (95% CIs) for elderly patients (those 75-85 years old) were only 0.88 (95% CI, 0.84-0.92), 0.88 (95% CI, 0.82-0.95), 0.76 (95% CI, 0.69-0.84), and 0.65 (95% CI, 0.61-0.70), for the same 4 cancer sites, respectively. A similar, although weaker, age-related period effect was observed for lung and pancreatic cancers. The adjusted HRs (95% CIs) for lung cancer were 0.75 (95% CI, 0.73-0.77) and 0.84 (95% CI, 0.81-0.86), respectively, for patients aged 50 to 64 years and 75 to 85 years diagnosed between 2005 and 2009, compared with the same age groups of patients diagnosed between 1990 and 1994 (0.73 [95% CI, 0.69-0.77] and 0.90 [95% CI, 0.85-0.95], respectively. Compared with whites or Asians, African Americans experienced greater improvement in prostate cancer survival. From 1990 to 2009, ovarian cancer survival declined among African Americans but improved among whites. No apparent sex difference in the degree of improvement for any non-sex-specific cancer was noted.

CONCLUSIONS AND RELEVANCE

Younger patients experienced greater benefit from recent oncology advances than elderly patients. African Americans experienced poorer survival than whites for all cancers, and the racial difference decreased for prostate cancer but increased for ovarian cancer. Identifying factors associated with varied improvement in cancer survival can inform future improvements in cancer care for all.

Surgical Resection of the Primary Tumor in Stage IV Colorectal Cancer Without Metastasectomy is Associated With Improved Overall Survival Compared With Chemotherapy/Radiation Therapy Alone

BACKGROUND

Controversy exists over whether resection of the primary tumor in stage IV colorectal cancer with inoperable metastases improves patient outcomes.

OBJECTIVE

The purpose of this study was to evaluate whether resection of the primary tumor without metastasectomy in patients with stage IV colorectal cancer is associated with improved overall survival compared with patients undergoing chemotherapy and/or radiation therapy alone.

DESIGN

This was a retrospective review of a multi-institutional dataset.

SETTINGS

This study was conducted in all participating commission on cancer (CoC)-accredited facilities.

PATIENTS

The 2003-2006 National Cancer Data Base was reviewed to identify patients with stage IV adenocarcinoma of the colon or rectum who underwent palliative treatment without curative intent, either in the form of surgical resection of the primary tumor without metastasectomy consisting of a colectomy or rectal resection with or without chemotherapy and/or radiation or chemotherapy and/or radiation alone.

MAIN OUTCOME MEASURES

Groups were compared for baseline characteristics. Overall survival was compared using Kaplan-Meier analysis before and after propensity matching with a 1:1 nearest-neighbor algorithm.

RESULTS

Of the 1446 patients included in the analysis, 231 (16%) underwent surgical resection of the primary tumor without metastasectomy. Surgical resection was associated with a significant survival benefit on unadjusted analysis (median survival, 9.2 vs. 7.6 months; p < 0.01). After propensity matching to adjust for nonrandom treatment selection, surgical resection continued to be associated with a significant survival benefit (median survival, 9.2 vs. 7.3 months; p < 0.01).

LIMITATIONS

This study was limited by the potential for selection bias regarding which patients received surgical resection. There was also a lack of data regarding the indication for operation, specifically whether a patient was symptomatic or asymptomatic before resection. The inability to account for tumor size or grade among patients who did not receive surgical resection was another limitation.

CONCLUSIONS

Surgical resection of the primary tumor without metastasectomy in patients with metastatic colorectal cancer is associated with improved survival as compared with chemotherapy/radiation therapy alone. Additional research is necessary to determine which patients may benefit from this intervention.