The purpose of our study was to characterize the causes of death among cancer patients as a function of objectives: (i) calendar year, (ii) patient age, and (iii) time after diagnosis. US death certificate data in Surveillance, Epidemiology, and End Results Stat 8.2.1 were used to categorize cancer patient death as being due to index-cancer, nonindex-cancer, and noncancer cause from 1973 to 2012. In addition, data were characterized with standardized mortality ratios (SMRs), which provide the relative risk of death compared with all persons. The greatest relative decrease in index-cancer death (generally from > 60% to < 30%) was among those with cancers of the testis, kidney, bladder, endometrium, breast, cervix, prostate, ovary, anus, colorectum, melanoma, and lymphoma. Index-cancer deaths were stable (typically >40%) among patients with cancers of the liver, pancreas, esophagus, and lung, and brain. Noncancer causes of death were highest in patients with cancers of the colorectum, bladder, kidney, endometrium, breast, prostate, testis; >40% of deaths from heart disease. The highest SMRs were from nonbacterial infections, particularly among 1,000 for lymphomas, P < 0.001). The highest SMRs were typically within the first year after cancer diagnosis (SMRs 10–10,000, P < 0.001). Prostate cancer patients had increasing SMRs from Alzheimer's disease, as did testicular patients from suicide. The risk of death from index- and nonindex-cancers varies widely among primary sites. Risk of noncancer deaths now surpasses that of cancer deaths, particularly for young patients in the year after diagnosis.

Purpose: The incidence rates of colorectal cancers are increasing in young adults. The objective of this study was to investigate genomic differences between tumor samples collected from younger and older patients with colorectal cancer. Experimental Design: DNA was extracted from 18,218 clinical specimens, followed by hybridization capture of 3,769 exons from 403 cancer-related genes and 47 introns of 19 genes commonly rearranged in cancer. Genomic alterations (GA) were determined, and association with patient age and microsatellite stable/microsatellite instability high (MSS/MSI-H) status established. Results: Overall genomic alteration rates in the younger (<40) and older (≥50) cohorts were similar in the majority of the genes analyzed. Gene alteration rates in the microsatellite stable (MSS) younger and older cohorts were largely similar, with several notable differences. In particular, TP53 (FDR < 0.01) and CTNNB1 (FDR = 0.01) alterations were more common in younger patients with colorectal cancer, and APC (FDR < 0.01), KRAS (FDR < 0.01), BRAF (FDR < 0.01), and FAM123B (FDR < 0.01) were more commonly altered in older patients with colorectal cancer. In the MSI-H cohort, the majority of genes showed similar rate of alterations in all age groups, but with significant differences seen in APC (FDR < 0.01), BRAF (FDR < 0.01), and KRAS (FDR < 0.01). Conclusions: Tumors from younger and older patients with colorectal cancer demonstrated similar overall rates of genomic alteration. However, differences were noted in several genes relevant to biology and response to therapy. Further study will need to be conducted to determine whether the differences in gene alteration rates can be leveraged to provide personalized therapies for young patients with early-onset sporadic colorectal cancer.

Colorectal cancer (CRC) is increasingly appreciated as a heterogeneous disease, with factors such as microsatellite instability (MSI), cancer subsite within the colon versus rectum, and age of diagnosis associated with specific disease course and therapeutic response. Activating oncogenic mutations in KRAS and NRAS are common in CRC, driving tumor progression and influencing efficacy of both cytotoxic and targeted therapies. The RAS mutational spectrum differs substantially between tumors arising from distinct tissues. Structure-function analysis of relatively common somatic RAS mutations in G12, Q61, and other codons is characterized by differing potency and modes of action. Here we show the mutational profile of KRAS, NRAS, and the less common HRAS in 13,336 CRC tumors, comparing the frequency of specific mutations based on age of diagnosis, MSI status, and colon versus rectum subsite. We identify mutation hotspots, and unexpected differences in mutation spectrum, based on these clinical parameters.

Loss of expression or activity of the tumor suppressor PTEN acts similarly to an activating mutation in the oncogene PIK3CA in elevating intracellular levels of phosphatidylinositol (3,4,5)-trisphosphate (PIP3), inducing signaling by AKT and other pro-tumorigenic signaling proteins. Here, we analyze sequence data for 34,129 colorectal cancer (CRC) patients, capturing 3,434 PTEN mutations. We identify specific patterns of PTEN mutation associated with microsatellite stability/instability (MSS/MSI), tumor mutational burden (TMB), patient age, and tumor location. Within groups separated by MSS/MSI status, this identifies distinct profiles of nucleotide hotspots, and suggests differing profiles of protein-damaging effects of mutations. Moreover, discrete categories of PTEN mutations display non-identical patterns of co-occurrence with mutations in other genes important in CRC pathogenesis, including KRAS, APC, TP53, and PIK3CA. These data provide context for clinical targeting of proteins upstream and downstream of PTEN in distinct CRC cohorts.