Project description:Approximately 50% of patients with primary colorectal carcinoma develop liver metastases. Understanding the genetic differences between primary colon cancer and their metastases to the liver is essential for devising a better therapeutic approach for this disease. We performed whole exome sequencing and copy number analysis for 15 triplets, each comprising normal colorectal tissue, primary colorectal carcinoma, and its synchronous matched liver metastasis. We analyzed the similarities and differences between primary colorectal carcinoma and matched liver metastases in regards to somatic mutations and somatic copy number alterationss. The genomic profiling demonstrated mutations in APC(73%), KRAS (33%), ARID1A and PIK3CA (6.7%) genes between primary colorectal and metastatic liver tumors. TP53 mutation was observed in 47% of the primary samples and 67% in liver metastatic samples. The grouped pairs, in hierarchical clustering showed similar somatic copy number alteration patterns, in contrast to the ungrouped pairs. Many mutations (including those of known key cancer driver genes) were shared in the grouped pairs. The ungrouped pairs exhibited distinct mutation patterns with no shared mutations in key driver genes. Four ungrouped liver metastasis samples had mutations in DNA mismatch repair genes along with hypermutations and a substantial number of copy number alterations. Our results suggest that about half of the metastatic colorectal carcinoma had the same clonal origin with their primary colorectal carcinomas, whereas remaining cases were genetically distinct from their primary carcinomas. These findings underscore the need to evaluate metastatic lesions separately for optimized therapy, rather than to extrapolate from primary tumor data.
Project description:Colorectal cancer is the second leading cause of cancer death in the United States, with over 50,000 deaths estimated in 2014. Molecular profiling for somatic mutations that predict absence of response to anti-EGFR therapy has become standard practice in the treatment of metastatic colorectal cancer; however, the quantity and type of tissue available for testing is frequently limited. Further, the degree to which the primary tumor is a faithful representation of metastatic disease has been questioned. As next-generation sequencing technology becomes more widely available for clinical use and additional molecularly targeted agents are considered as treatment options in colorectal cancer, it is important to characterize the extent of tumor heterogeneity between primary and metastatic tumors.We performed deep coverage, targeted next-generation sequencing of 230 key cancer-associated genes for 69 matched primary and metastatic tumors and normal tissue. Mutation profiles were 100% concordant for KRAS, NRAS, and BRAF, and were highly concordant for recurrent alterations in colorectal cancer. Additionally, whole genome sequencing of four patient trios did not reveal any additional site-specific targetable alterations.Colorectal cancer primary tumors and metastases exhibit high genomic concordance. As current clinical practices in colorectal cancer revolve around KRAS, NRAS, and BRAF mutation status, diagnostic sequencing of either primary or metastatic tissue as available is acceptable for most patients. Additionally, consistency between targeted sequencing and whole genome sequencing results suggests that targeted sequencing may be a suitable strategy for clinical diagnostic applications.
Project description:BackgroundMultiple synchronous lung tumors (MSLT), particularly within a single lobe, represent a diagnostic and treatment challenge. While histologic assessment was once the only method to possibly distinguish multiple primary lung cancers, there is a growing interest in identifying unique genomic features or mutations to best characterize these processes.MethodsIn order to differentiate multiple primary lung malignancies from intrapulmonary metastases in patients with MSLT, we performed whole exome sequencing (WES) on 10 tumor samples from 4 patients with MSLT.ResultsShared mutations between tumors from the same patient varied from 0-91%. Patient 3 shared no common mutations; however, in Patients 2 and 4, identical mutations were identified among all tumors from each patient, suggesting that the three tumors identified in Patient 3 represent separate primary lung cancers, while those of Patients 1, 2 and 4 signify hematogenous and lymphatic spread.ConclusionsA high proportion of shared mutations between different lung tumors is likely indicative of intrapulmonary metastatic disease, while tumors with distinct genomic profiles likely represent multiple primary malignancies driven by distinct molecular events. Application of genomic profiling in the clinical setting may prove to be important to precise management of patients with MSLT.
Project description:PurposeAlthough the mutation status of KRAS is highly concordant in primary and metastatic lesions, it has not been generalized to other major pathway genes.Materials and methodsIn this study, 41 genes were evaluated and the mutational profiles were compared in 46 colorectal cancer patients with paired surgical specimens of primary and metastatic lesions: synchronous (n=27) and metachronous (n=19) lesions. A high-throughput mass spectrometry-based genotyping platform validated by orthogonal chemistry, OncoMap v.4.4, was used to evaluate the formalin-fixed, paraffin-embedded surgical specimens. The patients' demographics, tumor characteristics, and microsatellite instability status were analyzed by a retrospective chart review.ResultsIn this study,with OncoMap, mutationswere identified in 80.4% of patientswith the following frequency: KRAS (39.1%), TP53 (28.3%), APC (28.3%), PIK3CA (6.5%), BRAF (6.5%), and NRAS (4.3%). Although 19.6% (9/46) of the patients showed no gene mutations, 43.5% (20/46) and 37.0% (17/46) had mutations in one and two or more genes, respectively. The synchronous and metachronous lesions showed similar mutational profiles. Paired samples between primary and metastatic tumors differed in 7.4% (2/27) and 10.5% (2/19) for synchronous and metachronous according to OncoMap.ConclusionThese findings indicate the major pathway genes, including KRAS, TP53, APC, PIK3CA, BRAF, and NRAS, are often concordant between the primary and metastatic lesions regardless of the temporal relationship of metastasis.
Project description:In cases of multiple lung cancers, individual tumors may represent either a primary lung cancer or both primary and metastatic lung cancers. Treatment selection varies depending on such features, and this discrimination is critically important in predicting prognosis. The present study was undertaken to determine the efficacy and validity of mutation analysis as a means of determining whether multiple lung cancers are primary or metastatic in nature. The study involved 12 patients who underwent surgery in our department for multiple lung cancers between July 2014 and March 2016. Tumor cells were collected from formalin-fixed paraffin-embedded tissues of the primary lesions by using laser capture microdissection, and targeted sequencing of 53 lung cancer-related genes was performed. In surgically treated patients with multiple lung cancers, the driver mutation profile differed among the individual tumors. Meanwhile, in a case of a solitary lung tumor that appeared after surgery for double primary lung cancers, gene mutation analysis using a bronchoscopic biopsy sample revealed a gene mutation profile consistent with the surgically resected specimen, thus demonstrating that the tumor in this case was metastatic. In cases of multiple lung cancers, the comparison of driver mutation profiles clarifies the clonal origin of the tumors and enables discrimination between primary and metastatic tumors.
Project description:The role of upfront primary tumor resection (PTR) in patients with unresectable metastatic colorectal cancer without severe symptoms remains controversial. We retrospectively analyzed the role of PTR in overall survival (OS) in this population. Among the 205 patients who enrolled, the PTR group (n = 42) showed better performance (p = 0.061), had higher frequencies of right-sided origin (p = 0.058), the T4 stage (p = 0.003), the M1a stage (p = 0.012), and <2 organ metastases (p = 0.002), and received fewer targeted agents (p = 0.011) than the chemotherapy group (n = 163). The PTR group showed a trend for longer OS (20.5 versus 16.0 months, p = 0.064) but was not related to OS in Cox regression multivariate analysis (p = 0.220). The male sex (p = 0.061), a good performance status (p = 0.078), the T3 stage (p = 0.060), the M1a stage (p = 0.042), <2 organ metastases (p = 0.035), an RAS wild tumor (p = 0.054), and the administration of targeted agents (p = 0.037), especially bevacizumab (p = 0.067), seemed to be related to PTR benefits. Upfront PTR could be considered beneficial in some subgroups, but these findings require larger studies to verify.
Project description:PurposeCombined resection of primary colorectal cancer and associated liver metastases is increasingly common. This study compares peri-operative and oncological outcomes according to surgical approach.MethodsThe study was registered with PROSPERO. A systematic search was performed for all comparative studies describing outcomes in patients that underwent laparoscopic versus open simultaneous resection of colorectal primary tumours and liver metastases. Data was extracted and analysed using a random effects model via Rev Man 5.3 RESULTS: Twenty studies were included with a total of 2168 patients. A laparoscopic approach was performed in 620 patients and an open approach in 872. There was no difference in the groups for BMI (mean difference: 0.04, 95% CI: 0.63-0.70, p = 0.91), number of difficult liver segments (mean difference: 0.64, 95% CI:0.33-1.23, p = 0.18) or major liver resections (mean difference: 0.96, 95% CI: 0.69-1.35, p = 0.83). There were fewer liver lesions per operation in the laparoscopic group (mean difference 0.46, 95% CI: 0.13-0.79, p = 0.007). Laparoscopic surgery was associated with shorter length of stay (p < 0.00001) and less overall postoperative complications (p = 0.0002). There were similar R0 resection rates (p = 0.15) but less disease recurrence in the laparoscopic group (mean difference: 0.57, 95% CI:0.44-0.75, p < 0.0001).ConclusionSynchronous laparoscopic resection of primary colorectal cancers and liver metastases is a feasible approach in selected patients and does not demonstrate inferior peri-operative or oncological outcomes.
Project description:BackgroundApproximately 4% of colorectal cancer (CRC) patients have at least two simultaneous cancers in the colon. Due to the shared environment, these synchronous CRCs (SCRCs) provide a unique setting to study colorectal carcinogenesis. Understanding whether these tumours are genetically similar or distinct is essential when designing therapeutic approaches.MethodsWe performed exome sequencing of 47 primary cancers and corresponding normal samples from 23 patients. Additionally, we carried out a comprehensive mutational signature analysis to assess whether tumours had undergone similar mutational processes and the first immune cell score analysis (IS) of SCRC to analyse the interplay between immune cell invasion and mutation profile in both lesions of an individual.ResultsThe tumour pairs shared only few mutations, favouring different mutations in known CRC genes and signalling pathways and displayed variation in their signature content. Two tumour pairs had discordant mismatch repair statuses. In majority of the pairs, IS varied between primaries. Differences were not explained by any clinicopathological variable or mutation burden.ConclusionsThe study shows major diversity within SCRCs. Rather than rely on data from one tumour, our study highlights the need to evaluate both tumours of a synchronous pair for optimised targeted therapy.
Project description:Liver metastasis is the major cause of death following a diagnosis of colorectal cancer (CRC). In this study, we compared the copy number profiles of paired primary and liver metastatic CRC to better understand how the genomic structure of primary CRC differs from the metastasis. Paired primary and metastatic tumors from 16 patients and their adjacent normal tissue samples were analyzed using single nucleotide polymorphism arrays. Genome-wide chromosomal copy number alterations were assessed, with particular attention to 188 genes known to be somatically altered in CRC and 24 genes that are clinically actionable in CRC. These data were analyzed with respect to the timing of primary and metastatic tissue resection and with exposure to chemotherapy. The genomic differences between the tumor and paired metastases revealed an average copy number discordance of 22.0%. The pairs of tumor samples collected prior to treatment revealed significantly higher copy number differences compared to post-therapy liver metastases (P = 0.014). Loss of heterozygosity acquired in liver metastases was significantly higher in previously treated liver metastasis samples compared to treatment naive liver metastasis samples (P = 0.003). Amplification of the clinically actionable genes ERBB2, FGFR1, PIK3CA or CDK8 was observed in the metastatic tissue of 4 patients but not in the paired primary CRC. These examples highlight the intra-patient genomic discrepancies that can occur between metastases and the primary tumors from which they arose. We propose that precision medicine strategies may therefore identify different actionable targets in metastatic tissue, compared to primary tumors, due to substantial genomic differences.
Project description:To analyze the possible clonal origin of a part of Synchronous colorectal cancer (SCRC), we studied 104 paired-SCRCs from 52 consecutive patients without hereditary forms of CRC. We used a Single-Nucleotide Polymorphism array to characterize the genomic profiles, and subsequently used a statistical application to define them according to clonality within the same individual. We categorized the ensuing groups according to colonic location to identify differential phenotypes. The SCRC Monoclonal group (M) (19 cases) was divided into Monosegmental (MM) and Pancolonic (MP) groups. The SCRC Polyclonal group (P) (33 cases) was also divided into Monosegmental (PM) and Pancolonic (PP), the first exhibiting preference for left colon. The MM group showed a high rate of mucinous tumors, the lowest mean-number of tumors and associated-polyps, and the worst prognosis. The MP group included the largest mean-number of associated-polyps, best prognosis and familial cancer component. The PM group seemed to be a "frontier" group. Finally, the PP group also exhibited a mucin component, the highest mean-number of tumors (4.6) compared with the mean-number of polyps (7.7), poor prognosis and sporadic cases. Most relevant differential genomic regions within M groups were gains on 1q24 and 8q24, and deletions on 1p21 and 1p23 for MM, while within P were the gains on 7q36 and deletions on 1p36 for PM. The statistical application employed seems to define clonality more accurately in SCRC -more likely to be polyclonal in origin-, and together with the tumor locations, helped us to configure a classification with prognostic and clinical value.