Genomic Landscape of Lynch Syndrome Colorectal Neoplasia Identifies Shared Mutated Neoantigens for Immunoprevention.

BACKGROUND & AIMS: Lynch syndrome (LS) carriers develop mismatch repair-deficient neoplasia with high neoantigen (neoAg) rates. No detailed information on targetable neoAgs from LS precancers exists, which is crucial for vaccine development and immune-interception strategies. We report a focused somatic mutation and frameshift-neoAg landscape of microsatellite loci from colorectal polyps without malignant potential (PWOMP), precancers, and early-stage cancers in LS carriers. METHODS: We generated paired whole-exome and transcriptomic sequencing data from 8 colorectal PWOMP, 41 precancers, 8 advanced precancers, and 12 early-stage cancers of 43 LS carriers. A computational pipeline was developed to predict, rank, and prioritize the top 100 detected mutated neoAgs that were validated in vitro using ELISpot and tetramer assays. RESULTS: Mutation calling revealed >10 mut/Mb in 83% of cancers, 63% of advanced precancers, and 20% of precancers. Cancers displayed an average of 616 MHC-I neoAgs/sample, 294 in advanced precancers, and 107 in precancers. No neoAgs were detected in PWOMP. A total of 65% of our top 100 predicted neoAgs were immunogenic in vitro, and were present in 92% of cancers, 50% of advanced precancers, and 29% of precancers. We observed increased levels of naïve CD8+ and memory CD4+ T cells in mismatch repair-deficient cancers and precancers via transcriptomics analysis. CONCLUSIONS: Shared frameshift-neoAgs are generated within unstable microsatellite loci at initial stages of LS carcinogenesis and can induce T-cell responses, generating opportunities for vaccine development, targeting LS precancers and early-stage cancers.

Comparative molecular genomic analyses of a spontaneous rhesus macaque model of mismatch repair-deficient colorectal cancer.

Colorectal cancer (CRC) remains the third most common cancer in the US with 15% of cases displaying Microsatellite Instability (MSI) secondary to Lynch Syndrome (LS) or somatic hypermethylation of the MLH1 promoter. A cohort of rhesus macaques from our institution developed spontaneous mismatch repair deficient (MMRd) CRC with a notable fraction harboring a pathogenic germline mutation in MLH1 (c.1029C

Repeat Cytoreduction and Hyperthermic Intraperitoneal Chemotherapy for Recurrent Mucinous Appendiceal Adenocarcinoma: A Viable Treatment Strategy with Demonstrable Benefit.

INTRODUCTION: Many patients with mucinous appendiceal adenocarcinoma experience peritoneal recurrence despite complete cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). Prior work has demonstrated that repeat CRS/HIPEC can prolong survival in select patients. We sought to validate these findings using outcomes from a high-volume center. PATIENTS AND METHODS: Patients with mucinous appendiceal adenocarcinoma who underwent CRS/HIPEC at MD Anderson Cancer Center between 2004 and 2021 were stratified by whether they underwent CRS/HIPEC for recurrent disease or as part of initial treatment. Only patients who underwent complete CRS/HIPEC were included. Initial and recurrent groups were compared. RESULTS: Of 437 CRS/HIPECs performed for mucinous appendiceal adenocarcinoma, 50 (11.4%) were for recurrent disease. Patients who underwent CRS/HIPEC for recurrent disease were more often treated with an oxaliplatin or cisplatin perfusion (35%/44% recurrent vs. 4%/1% initial, p < 0.001), had a longer operative time (median 629 min recurrent vs. 511 min initial, p = 0.002), and had a lower median length of stay (10 days repeat vs. 13 days initial, p < 0.001). Thirty-day complication and 90-day mortality rates did not differ between groups. Both cohorts enjoyed comparable recurrence free survival (p = 0.82). Compared with patients with recurrence treated with systemic chemotherapy alone, this select cohort of patients undergoing repeat CRS/HIPEC enjoyed better overall survival (p < 0.001). CONCLUSIONS: In appropriately selected patients with recurrent appendiceal mucinous adenocarcinoma, CRS/HIPEC can provide survival benefit equivalent to primary CRS/HIPEC and that may be superior to that conferred by systemic therapy alone in select patients. These patients should receive care at a high-volume center in the context of a multidisciplinary team.

Anatomic Basis of Rectal Cancer Staging: Clarifying Controversies and Misconceptions.

Rectal MRI provides a detailed depiction of pelvic anatomy; specifically, the relationship of the tumor to key anatomic structures, including the mesorectal fascia, anterior peritoneal reflection, and sphincter complex. However, anatomic inconsistencies, pitfalls, and confusion exist, which can have a strong impact on interpretation and treatment. These areas of confusion include the definition of the rectum itself, specifically differentiation of the rectum from the anal canal and the sigmoid colon, and delineation of the high versus low rectum. Other areas of confusion include the relative locations of the mesorectal fascia and peritoneum and their significance in staging and treatment, the difference between the mesorectal fascia and circumferential resection margin, involvement of the sphincter complex, and evaluation of lateral pelvic lymph nodes. The impact of these anatomic inconsistencies and sources of confusion is significant, given the importance of MRI in depicting the anatomic relationship of the tumor to critical pelvic structures, to triage surgical resection and neoadjuvant chemoradiotherapy with the goal of minimizing local recurrence. Evolving treatment paradigms also place MRI central in management of rectal cancer. ©RSNA, 2024.

Treatment Variation and Long-Term Outcomes of Low-Grade Appendiceal Neoplasms.

BACKGROUND: Heterogenous nomenclature describing appendiceal neoplasms has added to uncertainty around their appropriate treatment. Although a recent consensus has established the term low-grade appendiceal neoplasm (LAMN), we hypothesize that significant variation remains in the treatment of LAMNs. METHODS: We retrospectively reviewed our prospectively maintained appendiceal registry, identifying patients with LAMNs from 2009 to 2019. We assessed variability in treatment, including whether patients underwent colectomy, spread of disease at presentation, and long-term outcomes. RESULTS: Of 136 patients with LAMNs, 88 (35%) presented with localized disease and 48 (35%) with disseminated peritoneal disease. Median follow-up was 2.9 years (IQR 1.9-4.4), and 120 (88%) patients underwent pre-referral surgery. Among 26 pre-referral colectomy patients, 23 (88%) were performed for perceived oncologic need/nodal evaluation; no nodal metastases were identified. In patients with resected LAMNs without radiographic evidence of disseminated disease, 41 (47%) underwent second look diagnostic laparoscopy (DL) to evaluate for occult metastases. No peritoneal metastases were identified. Patients with disseminated disease were treated with cytoreductive surgery/heated intraperitoneal chemotherapy (CRS/HIPEC). For patients undergoing CRS/HIPEC, 5-year recurrence-free survival was 94% (95% CI 81-98%). For patients with localized disease, 5-year RFS was 98% (95% CI 85-99%). CONCLUSIONS: Significant variation exists in treatment patterns for LAMNs, particularly prior to referral to a high-volume center. Patients frequently underwent colectomy without apparent oncologic benefit. In the current era of high-quality cross sectional imaging, routine use of DL has low yield and is not recommended. Recurrence in this population is rare, and low-intensity surveillance can be offered. Overall prognosis is excellent, even with peritoneal disease.

Prognostic significance of acellular mucin in patients undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) for appendiceal neoplasms.

INTRODUCTION: Appendiceal neoplasms have a propensity for peritoneal dissemination. The standard of care for select individuals is CRS/HIPEC. In the current 8th AJCC Staging system, a finding of only intraperitoneal acellular mucin (M1a) is classified as Stage IVa. There is concern that the current AJCC system may over-stage patients. METHODS: This was a single-institution retrospective review of 164 cases of mucinous appendiceal neoplasm. Patients undergoing CRS/HIPEC with M1a disease were compared to patients with peritoneal deposits containing tumor cells (well-differentiated adenocarcinoma; low-grade mucinous carcinoma peritonei-M1b,G1). Overall and recurrence-free survival were assessed. RESULTS: Median age was 51 years, 70% were female, and 75% White. Sixty-four patients had M1a disease and 100 M1b,G1 disease. M1a disease had a lower median PCI score (11 vs. 20, p = .0001) and a higher rate of complete CRS (62% vs. 50%, p = .021). Median follow-up was 7.6 years (IQR 5.6-10.5 years). For M1a disease, there were no recurrences and only one patient died during the study interval. In comparison, for M1b disease, 66/100 (66%) recurred with a 5-year RFS of 40.5% (HR 8.0, 95% CI 4.9-15.1, p < .0001), and 31/100 (31%) died with a 5-year OS of 84.8% (HR 4.5, 95% CI 2.2-9.2, p < .0001). CONCLUSIONS: Acellular mucin (M1a disease) after CRS/HIPEC for appendiceal neoplasm is associated with longer OS and RFS compared to M1b, G1 disease. Current AJCC staging does not accurately reflect the differing outcomes of these two patient populations. The presence of acellular mucin in the peritoneal cavity should not be perceived as a metastatic equivalent.

Magnetic Resonance Imaging Directed Surgical Decision Making for Lateral Pelvic Lymph Node Dissection in Rectal Cancer After Total Neoadjuvant Therapy (TNT).

OBJECTIVE: Lateral pelvic lymph node (LPLN) metastases are an important cause of preventable local failure in rectal cancer. The aim of this study was to evaluate clinical and oncological outcomes following magnetic resonance imaging (MRI)-directed surgical selection for lateral pelvic lymph node dissection (LPLND) after total neoadjuvant therapy (TNT). METHODS: A retrospective consecutive cohort analysis was performed of rectal cancer patients with enlarged LPLN on pretreatment MRI. Patients were categorized as LPLND or non-LPLND. The main outcomes were lateral local recurrence rate, perioperative and oncological outcomes and factors associated with decision making for LPLND. RESULTS: A total of 158 patients with enlarged pretreatment LPLN and treated with TNT were identified. Median follow-up was 20 months (interquartile range 10-32). After multidisciplinary review, 88 patients (56.0%) underwent LPLND. Mean age was 53 (SD±12) years, and 54 (34.2%) were female. Total operative time (509 vs 429 minutes; P =0.003) was greater in the LPLND group, but median blood loss ( P =0.70) or rates of major morbidity (19.3% vs 17.0%) did not differ. LPLNs were pathologically positive in 34.1%. The 3-year lateral local recurrence rates (3.4% vs 4.6%; P =0.85) did not differ between groups. Patients with LPLNs demonstrating pretreatment heterogeneity and irregular margin (odds ratio, 3.82; 95% confidence interval: 1.65-8.82) or with short-axis ≥5 mm post-TNT (odds ratio 2.69; 95% confidence interval: 1.19-6.08) were more likely to undergo LPLND. CONCLUSIONS: For rectal cancer patients with evidence of LPLN metastasis, the appropriate selection of patients for LPLND can be facilitated by a multidisciplinary MRI-directed approach with no significant difference in perioperative or oncologic outcomes.

Prognosis for Poorly Differentiated, High-Grade Rectal Neuroendocrine Carcinomas.

INTRODUCTION: Rectal neuroendocrine carcinomas (rNECs) are poorly characterized and, given their aggressive nature, optimal management is not well-established. We therefore sought to describe clinicopathologic traits, treatment details, and survival patterns for patients with rNECs. METHODS: Patients captured in the National Cancer Database (NCDB; 2004-2016) with rNECs managed with observation, chemotherapy, or proctectomy ± chemotherapy were considered for analysis. RESULTS: The inclusion criteria were met by 777 patients. Mean age was 62.4 years, 45% were male, 80% were Caucasian, 40% presented with lymph nodes metastases, and 49% presented with distant metastases. Chemotherapy and surgical resection were administered in 72 and 19% of cases, respectively. Median overall survival (OS) was 0.83 years (1 year, 41%; 3 years, 13%; 5 years, 10%). During the study interval, 659 (85%) patients died, with a median follow-up of 0.79 years. On multivariable analysis, age ≥60 years, male sex, and distant metastases were associated with worse survival; surgical resection and administration of chemotherapy were associated with a reduced risk of death. Among non-metastatic patients treated with surgical resection, administration of chemotherapy was protective, while a positive lymph node ratio (LNR) ≥42% (median value) was associated with an increased risk of death. There was no difference in the number of examined lymph nodes between LNR cohorts. CONCLUSIONS: Patients with rNECs experience dismal survival outcomes, including those with non-metastatic disease treated with curative-intent surgical resection. Neoadjuvant therapy can serve as a useful biologic test, and surgical resection should be judiciously employed.

What is the Risk for Peritoneal Metastases and Survival Afterwards in T4 Colon Cancers?

BACKGROUND: Patients with T4 colon adenocarcinomas have an increased risk of peritoneal metastases (PM) but the histopathologic risk factors for its development are not well-described. OBJECTIVE: The purpose of this study was to determine factors associated with PM, time to recurrence, and survival after recurrence among patients with T4 colon cancer. PATIENTS AND METHODS: Patients with pathologic T4 colon cancer who underwent curative resection from 2005 to 2017 were identified from a prospectively maintained institutional database and classified by recurrence pattern: (a) none - 68.8%; (b) peritoneal only - 7.9%; (c) peritoneal and extraperitoneal - 9.9%; and (d) extraperitoneal only - 13.2%. Associations between PM development and patient, primary tumor, and treatment factors were assessed. RESULTS: Overall, 151 patients were analyzed, with a median follow-up of 66.2 months; 27 patients (18%) developed PM (Groups B and C) and 20 (13%) patients recurred at non-peritoneal sites only (Group D). Median time to developing metastases was shorter for Groups B and C compared with Group D (B and C: 13.7 months; D: 46.7 months; p = 0.022). Tumor deposits (TDs) and nodal stage were associated with PM (p < 0.05), and TDs (p = 0.048) and LVI (p = 0.015) were associated with additional extraperitoneal recurrence. Eleven (41%) patients with PM underwent salvage surgery, and median survival after recurrence was associated with the ability to undergo cytoreduction (risk ratio 0.20, confidence interval 0.06-0.70). CONCLUSION: PM risk after resection of T4 colon cancer is independently associated with factors related to lymphatic spread, such as N stage and TDs. Well-selected patients can undergo cytoreduction with long-term survival. These findings support frequent postoperative surveillance and aggressive early intervention, including cytoreduction.

Naproxen chemoprevention promotes immune activation in Lynch syndrome colorectal mucosa.

OBJECTIVE: Patients with Lynch syndrome (LS) are at markedly increased risk for colorectal cancer. It is being increasingly recognised that the immune system plays an essential role in LS tumour development, thus making an ideal target for cancer prevention. Our objective was to evaluate the safety, assess the activity and discover novel molecular pathways involved in the activity of naproxen as primary and secondary chemoprevention in patients with LS. DESIGN: We conducted a Phase Ib, placebo-controlled, randomised clinical trial of two dose levels of naproxen sodium (440 and 220 mg) administered daily for 6 months to 80 participants with LS, and a co-clinical trial using a genetically engineered mouse model of LS and patient-derived organoids (PDOs). RESULTS: Overall, the total number of adverse events was not different across treatment arms with excellent tolerance of the intervention. The level of prostaglandin E2 in the colorectal mucosa was significantly decreased after treatment with naproxen when compared with placebo. Naproxen activated different resident immune cell types without any increase in lymphoid cellularity, and changed the expression patterns of the intestinal crypt towards epithelial differentiation and stem cell regulation. Naproxen demonstrated robust chemopreventive activity in a mouse co-clinical trial and gene expression profiles induced by naproxen in humans showed perfect discrimination of mice specimens with LS and PDOs treated with naproxen and control. CONCLUSIONS: Naproxen is a promising strategy for immune interception in LS. We have discovered naproxen-induced gene expression profiles for their potential use as predictive biomarkers of drug activity. TRIAL REGISTRATION NUMBER: gov Identifier: NCT02052908.

MRI Staging in an Evolving Management Paradigm for Rectal Cancer, From the AJR Special Series on Cancer Staging.

The treatment of rectal cancer centers around the distinct but related goals of management of distant metastases and management of local disease. Optimal local management requires attention to the primary tumor and its anatomic relationship to surrounding pelvic structures, with the goal of minimizing local recurrence (LR). High-resolution MRI is ideally suited for this purpose; application of MRI-based criteria in conjunction with optimized surgical and pathologic techniques has successfully reduced LR rates. This success has led to a shift away from using the TNM-based National Comprehensive Cancer Network (NCCN) guidelines as the sole determinant of whether a patient receives neoadjuvant chemoradiation. The new model uses a hybrid approach for assigning risk categories that combines elements of the TNM staging system with MRI-based anatomic features. These risk categories incorporate tumor proximity to the circumferential resection margin, T category, distance to the anal verge, and presence of extramural venous invasion to classify rectal tumors as low, intermediate, or high risk. This approach has been validated by accumulated data from numerous multiinstitutional studies. This article illustrates key anatomic concepts, depicts common interpretive errors and pitfalls, and discusses ongoing limitations; these insights should guide radiologists in optimal rectal MRI interpretation.

Integrated clinico-molecular profiling of appendiceal adenocarcinoma reveals a unique grade-driven entity distinct from colorectal cancer.

BACKGROUND: Appendiceal adenocarcinoma (AA) is an orphan disease with unique clinical attributes but often treated as colorectal cancer (CRC). Understanding key molecular differences between AA and CRC is critical. METHODS: We performed retrospective analyses of AA patients (N = 266) with tumour and/or blood next-generation sequencing (NGS) (2013-2018) with in-depth clinicopathological annotation. Overall survival (OS) was examined. For comparison, CRC cohorts annotated for sidedness, consensus molecular subtypes (CMS) and mutations (N = 3283) were used. RESULTS: Blood-NGS identified less RAS/GNAS mutations compared to tissue-NGS (4.2% vs. 60.9%, P < 0.0001) and showed poor concordance with tissue for well-/moderately differentiated tumours. RAS (56.2%), GNAS (28.1%) and TP53 (26.9%) were most frequent mutations. Well/moderately differentiated tumours harboured more RAS (69.2%/64.0% vs. 40.5%) and GNAS (48.7%/32.0% vs. 10.1%) while moderate/poorly differentiated tumours had more TP53 (26.0%/27.8% vs. 7.7%) mutations. Appendiceal adenocarcinoma (compared to CRC) harboured significantly fewer APC (9.1% vs. 55.4%) and TP53 (26.9% vs. 67.5%) and more GNAS mutations (28.1% vs. 2.0%) (P < 0.0001). Appendiceal adenocarcinoma mutation profile did not resemble either right-sided CRC or any of the four CMS in CRC. High grade, but no mutation, was independently predictive of survival. CONCLUSION: Integrated clinico-molecular profiling of AA identified key molecular drivers distinct from CRC. Appendiceal adenocarcinoma has a predominantly grade-driven biology that trumps mutations.

Low-grade Appendiceal Mucinous Neoplasm of Uncertain Malignant Potential (LAMN-UMP): Prognostic Factors and Implications for Treatment and Follow-up.

BACKGROUND: Low-grade appendiceal mucinous neoplasm of uncertain malignant potential are poorly understood lesions characterized by extraluminal mucin or fibrosis with neoplastic cells confined to the appendiceal lumen. The purpose of this study is to investigate the clinical and pathologic parameters of these lesions to optimize our understanding and management of these tumors. METHODS: Subjects with these tumors were identified from the appendiceal tumor databases at the University of Texas MD Anderson Cancer Center. Univariate and multivariate Cox proportional hazards regression analyses assessed relationships between clinicopathologic variables [including age, gender, margin status and serum levels of the tumor markers carcinoembryonic antigen (CEA), cancer antigen (CA)-125, and CA19-9] disease-free survival, postrecurrence survival and overall survival. RESULTS: Ninety-eight subjects with this disease were identified. Most patients did not experience disease recurrence after initial appendectomy. At last follow-up, 25 (26 %) had disease recurrence or died. Of the 20 patients who had disease recurrence, 5 (25 %) died, and 15 (75 %) were alive. Disease-free survival was significantly reduced with positive margin status (p = 0.02) and elevated serum levels of CEA (p < 0.001), CA19-9 (p = 0.01), or CA-125 (p = 0.002) at the time of appendectomy. The median postrecurrence survival time was 4.7 years and the 5-year postrecurrence survival rate was 41 % (standard error = 18 %). CONCLUSIONS: Patients with Low-grade appendiceal mucinous neoplasm of uncertain malignant potential who have negative margins and normal tumor marker levels have a lower risk for recurrence. In these patients, expectant management is sufficient. Elevated tumor marker levels at the time of appendectomy marks an increased risk of recurrence or death and signals the need for closer monitoring or intervention.

Utility of Appendiceal Calcifications Detected on Computed Tomography as a Predictor for an Underlying Appendiceal Epithelial Neoplasm.

BACKGROUND: Mucinous appendiceal neoplasms can contain radiopaque calcifications. Whether appendiceal radiographic calcifications indicate the presence of an appendiceal epithelial neoplasm is unknown. This study aimed to determine whether appendiceal calcifications detected by computed tomography (CT) correlate with the presence of appendiceal epithelial neoplasms. METHODS: From prospective appendiceal and pathology databases, 332 cases of appendiceal neoplasm and 136 cases of control appendectomy were identified, respectively. Only cases with preoperative CT scans available for review were included in the study. Images were reviewed by two abdominal radiologists. Sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) were calculated, and the kappa statistic was used to determine agreement between the radiologists' interpretations. RESULTS: Interobserver agreement between the radiologists was substantial, with a kappa of 0.74. Appendiceal mural calcifications were identified on CT scans in 106 appendiceal neoplasm cases (32%) and in 1 control case (1%) (P = 0.0001). In the appendiceal neoplasm subgroup, the presence of radiographic calcifications was associated with mucinous histology (35% vs 17%; P = 0.006; odds ratio [OR], 0.38; 95% confidence interval [CI], 0.18-0.78) and with well-differentiated histologic grade (40% vs 24%; P = 0.002; OR, 0.47; 95% CI, 0.29-0.76). The findings showed a sensitivity of 31.9% (95% CI, 26.9-37.2%), a specificity of 99.3% (95% CI, 96-100%), a PPV of 99.1% (95% CI, 94.9-100%), and an NPV of 37.4% (95% CI, 32.4-42.6%). CONCLUSION: This case-control study showed that appendiceal mural calcifications detected on CT are associated with underlying appendiceal epithelial neoplasms and that the identification of incidental mural appendiceal calcifications may have an impact on decisions regarding surgical intervention.

Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Moderately and Poorly Differentiated Appendiceal Adenocarcinoma: Survival Outcomes and Patient Selection.

BACKGROUND: Moderately and poorly differentiated adenocarcinoma of the appendix represents an aggressive histological variant with a high risk of recurrence and death. METHODS: Overall, 178 patients with moderately and poorly differentiated appendiceal adenocarcinoma were identified from a prospective database. Clinical, pathologic, and treatment factors were analyzed for outcomes. RESULTS: Diagnostic laparoscopy (DL) identified radiographic occult peritoneal metastasis in 25 (42%) patients. These patients had a significantly lower peritoneal carcinomatosis index (PCI) and improved overall survival (OS) compared with those with radiographic disease. Twenty-seven (41%) patients were excluded from cytoreductive surgery (CRS) because of findings on DL, while 116 (65%) patients underwent CRS and hyperthermic intraperitoneal chemotherapy (HIPEC), with a median disease-free survival (DFS) of 23 months. Mucinous histology (hazard ratio [HR] 0.52, p = 0.04) and PCI (HR 1.054, p = 0.02) were independent predictors of DFS. The median OS following CRS and HIPEC was 48 months. Mucinous histology (HR 0.352, p = 0.018), signet ring cells (HR 3.34, p = 0.02), positive peritoneal cytology (HR 0.081, p = 0.04), and PCI (HR 1.076, p = 0.004) were independently associated with OS. Eight-five (73.3%) patients received neoadjuvant chemotherapy, and 40 (47.1%) patients achieved a radiographic response; 36 (42.3%) had stable disease, while 9 (10.6%) had progressive disease. Stable or responsive disease was associated with improved median OS of 44 months, compared with 21 months for those with progressive disease (p = 0.011). CONCLUSIONS: In selected patients, long-term survival can be obtained. Mucinous histology, absence of signet ring cells, negative peritoneal cytology, PCI ≤ 20, and response/stable disease after neoadjuvant chemotherapy are important selection criteria for CRS and HIPEC.

Is complete liver resection without resection of synchronous lung metastases justified?

BACKGROUND: Advances in multidisciplinary care are changing the prognostic impact of colorectal lung metastases. Resection of colorectal liver metastases (CLM) may benefit patients with synchronous lung metastases even when lung metastases are not resected. The aim of this study was to investigate the survival of patients undergoing complete resection of CLM in the setting of unresected lung metastases. PATIENTS AND METHODS: We compared survival among 98 patients who underwent resection of CLM with unresected lung metastases, 64 who received only chemotherapy for limited colorectal liver and lung metastases, and 41 who underwent resection of both liver and lung metastases. Prognostic factors were investigated in the patients who underwent resection of CLM only. RESULTS: The 3-year/5-year overall survival (OS) rates of patients with CLM resection only (42.9 %/13.1 %) were better than those of patients treated with chemotherapy only (14.1 %/1.6 %; p < 0.01) but worse than those of patients with resection of liver and lung metastases (68.9 %/56.9 %; p < 0.01). Multivariate analysis of patients with CLM resection only revealed that KRAS mutation [hazard ratio (HR) 2.10; 95 % confidence interval (CI) 1.21-3.64; p < 0.01] and rectal primary tumor (HR 1.72; 95 % CI 1.02-2.88; p = 0.04) were independent predictors of worse OS. Survival of patients without these risk factors was similar to that of patients with curative metastasectomy. CONCLUSIONS: Complete resection of metastases remains the primary goal of treatment for stage IV colorectal cancer. Resection of CLM without resection of lung metastases is associated with an intermediate survival between that of patients treated with palliative and curative intent and should be considered in selected patients.

A Prospective Six Sigma Quality Improvement Trial to Optimize Universal Screening for Genetic Syndrome Among Patients With Young-Onset Colorectal Cancer.

BACKGROUND: Improving the quality of health care is a national priority, and providing patient-centered care is one of the 6 key areas for quality improvement. In the setting of patients with young-onset colorectal cancer (CRC), appropriate genetic workup and testing for potential underlying inherited CRC syndromes is fundamental to patient-centered care. Lynch syndrome (LS) is the most common of these inherited syndromes, and current recommendations from the NCCN and other professional societies advocate universal screening for LS among young patients with CRC. However, practical implementation of these guidelines often falls short. METHODS: We conducted a prospective quality improvement intervention trial to optimize universal screening for LS in young (age <50 years) patients, involving 356 eligible patients during the 12-month preintervention period and 299 patients during the postintervention. RESULTS: Applying the Six Sigma conceptual framework, we demonstrated a significant increase in use of tumor-based molecular testing and subsequent confirmatory germline mutation testing for LS. This led to identification of more patients to be managed as having LS and of more first- and second-degree relatives to benefit from the testing results. CONCLUSIONS: This study demonstrated the successful application of a quality improvement conceptual framework for the universal adoption of molecular biomarker testing in patients with cancer, and for improving adherence to NCCN Clinical Practice Guidelines in Oncology for CRC Screening. As molecular and genetic testing is becoming increasingly common, we present a prototype study for improving the adoption of molecular studies and the provision of guideline-based patient-centered care.