The features associated with the mucinous histologic subtype were independent predictors for shorter OS, including BRAF (HR, 1.74; 95% CI, 1.35-2.25; P < .001) and KRAS (HR, 1.42; 95% CI, 1.22-1.65; P < .001) mutations, right-sided location (HR, 1.20; 95% CI, 1.04-1.39; P = .01), and synchronous metastases (HR, 2.92; 95% CI, 2.49-3.42; P < .001).
Compared with KRAS codon 12 mutations, codon 13-mutated mCRC presents as a more aggressive disease frequently associated with local and distant metastases at first diagnosis.
Treatments including the monoclonal antibodies showed a cost per month of PFS gained of 2823 € (FOLFIRI with cetuximab in KRAS wild-type patients and liver-only metastases), of € 15,822 (FOLFOX with panitumumab in KRAS wild type), and of 13,383 € (FOLFOX with bevacizumab).
The mutant allele frequency of KRAS in metachronous metastases was higher in 6 cases (mean difference =% 25.5% (range, 9.5%-58.0%)) and lower in 3 cases (mean difference = 9.3% (range, 8.0-10.0%) compared with each of their primary tumors.
At multivariable analysis, significant association with pathological response was found for number of resected metastases (p = 0.015) and bevacizumab allocation (p < 0.001), while KRAS mutation showed only a trend.
Heterogeneity of KRAS status consisted in KRAS mutated in (i) the primary tumour but not in its synchronous metastasis, (ii) the metastasis but not in the primary tumour, (iii) the pelvic recurrence but not in the primary tumour, (iiii) some metastases and not in others from the same patient.
On the other hand, our data indicate that the K-RAS mutational status of the primary tumor does not predict the status of the bone metastatic tissue of NSCLC, since we have observed both emergence of mutant clones in metastases from wild-type (wt) primary tumors and loss of mutant clones in metastases from mutant primaries in addition to the maintained mutant status.
KRAS-mutant NSCLC patients with concurrent LKB1 loss had a higher number of metastatic sites at the time of diagnosis (median 2.5 vs. 2, P = 0.01), higher incidence of extrathoracic metastases (P = 0.01), and developed brain metastasis more frequently (48% vs. 25%, P = 0.02).
Increased LOH at KRAS was also observed in progression of human pancreatic primary tumors to metastases, again supporting a role for the KRAS gene in cancer metastasis.
In particular, mutations in Kirsten rat sarcoma viral oncogene homolog gene (KRAS), alone or in combination with tumor protein p53 gene (TP53) mutations, were associated with decreased survival probability and with the occurrence of local metastases at recurrence.
Methods The data of patients with lung metastases from colon cancer who underwent SABR were retrospectively evaluated according to the following inclusion criteria: number of metastases ≤3; lung oligometastases from colon cancer in patients who underwent SABR; patients receiving previous chemotherapy alone or in combination with bevacizumab; Karnofsky performance status >80; life expectancy >6 months; at least 6 months' follow-up after SABR; presence of KRAS mutation.
Patients whose tumors contain K-ras gene mutations are more likely to develop distant metastases and have lower median survival than patients without such mutations.
Mutations in KRAS were observed in 37 (34%) of primary tumors and in 40 (36%) of related metastases, yielding a 94% level of concordance (kappa index 0.86).
Survival was independently and unfavourably affected by the following variables: poor performance status, short time from initial diagnosis of metastases to the start of regorafenib, low initial regorafenib dose, >3 metastatic sites, presence of liver metastases, and KRAS mutations.
KRAS-mutated carcinomas were more frequently observed in female patients (47.5% vs 37.1%, p = 0.005) and mucinous differentiation (34.7% vs 24.8%, p = 0.004), but have no difference between lymph node (LN) metastases and among pTNM stages.