KRAS mutations occur in 35-45% of metastatic colorectal cancers (mCRC) and preclude responsiveness to EGFR-targeted therapy with cetuximab or panitumumab. However, less than 20% patients displaying ...wild-type KRAS tumors achieve objective response. Alterations in other effectors downstream of the EGFR, such as BRAF, and deregulation of the PIK3CA/PTEN pathway have independently been found to give rise to resistance. We present a comprehensive analysis of KRAS, BRAF, PIK3CA mutations, and PTEN expression in mCRC patients treated with cetuximab or panitumumab, with the aim of clarifying the relative contribution of these molecular alterations to resistance.
We retrospectively analyzed objective tumor response, progression-free (PFS) and overall survival (OS) together with the mutational status of KRAS, BRAF, PIK3CA and expression of PTEN in 132 tumors from cetuximab or panitumumab treated mCRC patients. Among the 106 non-responsive patients, 74 (70%) had tumors with at least one molecular alteration in the four markers. The probability of response was 51% (22/43) among patients with no alterations, 4% (2/47) among patients with 1 alteration, and 0% (0/24) for patients with > or =2 alterations (p<0.0001). Accordingly, PFS and OS were increasingly worse for patients with tumors harboring none, 1, or > or =2 molecular alteration(s) (p<0.001).
When expression of PTEN and mutations of KRAS, BRAF and PIK3CA are concomitantly ascertained, up to 70% of mCRC patients unlikely to respond to anti-EGFR therapies can be identified. We propose to define as 'quadruple negative', the CRCs lacking alterations in KRAS, BRAF, PTEN and PIK3CA. Comprehensive molecular dissection of the EGFR signaling pathways should be considered to select mCRC patients for cetuximab- or panitumumab-based therapies.
The BRAFV600E mutation is found in 8–10% of metastatic colorectal cancer (mCRC) patients and it is recognized as a poor prognostic factor with a median overall survival inferior to 20 months. At ...present, besides immune checkpoint inhibitors (CPIs) for those tumors with concomitant MSI-H status, recommended treatment options include cytotoxic chemotherapy + anti-VEGF in the first line setting, and a combination of EGFR and a BRAF inhibitor (cetuximab plus encorafenib) in second line. However, even with the latter targeted approach, acquired resistance limits the possibility of more than an incremental benefit and survival is still dismal. In this review, we discuss current treatment options for this subset of patients and perform a systematic review of ongoing clinical trials. Overall, we identified six emerging strategies: targeting MAPK pathway (monotherapy or combinations), targeting MAPK pathway combined with cytotoxic agents, intensive cytotoxic regimen combinations, targeted agents combined with CPIs, oxidative stress induction, and cytotoxic agents combined with antiangiogenic drugs and CPIs. In the future, the integration of new therapeutic strategies targeting key players in the BRAFV600E oncogenic pathways with current treatment approach based on cytotoxic chemotherapy and surgery is likely to redefine the treatment landscape of these CRC patients.
Cancers of the Vater ampulla (ampullary cancers, ACs) account for less than 1% of all gastrointestinal tumors. ACs are usually diagnosed at advanced stage, with poor prognosis and limited therapeutic ...options. BRCA2 mutations are identified in up to 14% of ACs and, differently from other tumor types, therapeutic implications remain to be defined. Here, we report a clinical case of a metastatic AC patient in which the identification of a BRCA2 germline mutation drove a personalized multimodal approach with curative-intent.
A 42-year-old woman diagnosed with stage IV BRCA2 germline mutant AC underwent platinum-based first line treatment achieving major tumor response but also life-threatening toxicity. Based on this, as well as on molecular findings and expected low impact of available systemic treatment options, the patient underwent radical complete surgical resection of both primary tumor and metastatic lesions. Following an isolated retroperitoneal nodal recurrence, given the expected enhanced sensitivity to radiotherapy in BRCA2 mutant cancers, the patient underwent imaging-guided radiotherapy leading to long-lasting complete tumor remission. After more than 2 years, the disease remains radiologically and biochemically undetectable. The patient accessed a dedicated screening program for BRCA2 germline mutation carriers and underwent prophylactic bilateral oophorectomy.
Even considering the intrinsic limitations of a single clinical report, we suggest that the finding of BRCA germline mutations in ACs should be taken into consideration, together with other clinical variables, given their potential association with remarkable response to cytotoxic chemotherapy that might be burdened with enhanced toxicity. Accordingly, BRCA1/2 mutations might offer the opportunity of personalizing treatment beyond PARP inhibitors up to the choice of a multimodal approach with curative-intent.
The
mutation is found in 8-10% of metastatic colorectal cancer (mCRC) patients and it is recognized as a poor prognostic factor with a median overall survival inferior to 20 months. At present, ...besides immune checkpoint inhibitors (CPIs) for those tumors with concomitant MSI-H status, recommended treatment options include cytotoxic chemotherapy + anti-VEGF in the first line setting, and a combination of EGFR and a BRAF inhibitor (cetuximab plus encorafenib) in second line. However, even with the latter targeted approach, acquired resistance limits the possibility of more than an incremental benefit and survival is still dismal. In this review, we discuss current treatment options for this subset of patients and perform a systematic review of ongoing clinical trials. Overall, we identified six emerging strategies: targeting MAPK pathway (monotherapy or combinations), targeting MAPK pathway combined with cytotoxic agents, intensive cytotoxic regimen combinations, targeted agents combined with CPIs, oxidative stress induction, and cytotoxic agents combined with antiangiogenic drugs and CPIs. In the future, the integration of new therapeutic strategies targeting key players in the
oncogenic pathways with current treatment approach based on cytotoxic chemotherapy and surgery is likely to redefine the treatment landscape of these CRC patients.
Background
Patients with metastatic colorectal cancer (mCRC) refractory to standard therapies have a poor prognosis. In this setting, recruitment into clinical trials is warranted, and studies driven ...by selection according to individual tumor molecular characteristics are expected to provide added value.
Objective
We retrospectively analyzed data from patients with mCRC refractory to or following failure of standard therapies who were enrolled into phase I/II clinical studies at the Niguarda Cancer Center based on the presence of a specific molecular profile expected to represent the target of susceptibility to the experimental drug(s).
Patients and Methods
From June 2011 to May 2016, 2044 patients with mCRC underwent molecular screening. Eighty patients (3.9%) were enrolled in ad hoc studies; the median age was 60 years (range 36–86) and the median number of previous treatment lines was five (range 2–8). Molecular characteristics exploited within these studies were
MGMT
promoter hypermethylation (48.7%),
HER2
amplification (28.8%),
BRAF
V600E
mutation (20%), and novel gene fusions involving
ALK
or
NTRK
(2.5%).
Results
One patient (1%) had RECIST (Response Evaluation Criteria In Solid Tumors) complete response (CR), 13 patients (16.5%) experienced a partial response (PR), and 28 (35%) stable disease (SD). Median progression-free survival (PFS) was 2.8 months (range 2.63–3.83), with 24% of patients displaying PFS >5 months. Median growth modulation index (GMI) was 0.85 (range 0–15.61) and 32.5% of patients had GMI >1.33.
KRAS
exon 2 mutations were found in 38.5% of patients, and among the 78 patients with known
KRAS
status, those with wild-type tumors had longer PFS than those with mutated tumors (3.80 95% CI 2.80–5.03 vs. 2.13 months 95% CI 1.77–2.87, respectively,
p
= 0.001). Median overall survival (OS) was 7.83 months (range 7.17–9.33) for all patients, and patients with
KRAS
wild-type tumors had longer OS than those with mutated tumors (7.83 95% CI 7.33–10.80 vs. 7.18 months 95% CI 5.63–9.33, respectively,
p
= 0.06).
Conclusions
This single-institution retrospective study indicates that in a heavily pretreated population approximately 4% of mCRC tumors display a potential actionable molecular context suitable for therapeutic intervention. Application of molecular selection is challenging but improves clinical outcome even in later lines of treatment.
Abstract only
6003
Background: This is the first phase III study directly comparing CRT vs CET/RT in LASCCHN. Primary endpoints of this study were to compare: 1) overall survival (OS) of induction ...vs. no induction arms; 2) Grade 3-4 in-field toxicity of CRT vs. CET/RT. Preliminary toxicity results of concomitant treatments (primary endpoint for this comparison) were reported at the 2012 ASCO meeting. Here we present response rate and survival data for the two concomitant treatments (CRT vs. CET/RT), irrespective of induction chemotherapy. Methods: Untreated patients with unresectable LASCCHN, stage III-IV, ECOG PS 0–1 were randomized to a 2x2 factorial design: Arm A1: CRT (2 cycles of cisplatin/5fluorouracil concomitant to RT); Arm A2: CET/RT; Arm B1: 3 cycles of TPF followed by the same CRT; Arm B2:3 cycles of TPF followed by CET/RT. Results: A total of421 patients were randomized: 261 received CRT (131 Arm A1+ 130 Arm B1) and 160 received CET/RT (80 Arm A2+ 80 Arm B2). 82% were male; median age was 60y; PS of 0 (79%) or 1 (21%). Stage was III (32%) or IV (68%). Sites of disease were: oral cavity 20%, oropharynx 57%, hypopharynx: 23%. No significant differences were observed in patients’ characteristics distribution. At a median follow-up of 32.9 months, a total of 174 deaths occurred (204 required for final OS analysis). Data on activity and efficacy of CRT and CET/RT are shown in the Table. Conclusions: No significant differences were observed in response rate, progression free survival and OS between CRT and CET/RT. Pts are still being followed-up to assess OS of induction vs. no induction arms. Clinical trial information: NCT01086826. Table: see text
PDF
