Prognostic and predictive value of TP53 mutations in node-positive breast cancer patients treated with anthracycline- or anthracycline/taxane-based adjuvant therapy: results from the BIG 02-98 phase III trial

The Mutational Spectrum of Pre- and Post-Neoadjuvant Chemotherapy Triple-Negative Breast Cancers

The response of triple-negative breast cancer (TNBC) patients to pre-operative (neoadjuvant chemotherapy) is a critical factor of their outcome. To determine the effects of chemotherapy on the tumor genome and to identify mutations associated with chemoresistance and sensitivity, we performed whole exome sequencing on pre/post-chemotherapy tumors and matched lymphocytes from 26 patients. We observed great inter-tumoral heterogeneity with no gene mutated recurrently in more than four tumors besides TP53. Although the degree of response to chemotherapy in residual tumors was associated with more subclonal changes during chemotherapy, there was minimal evolution between pre/post-tumors. Indeed, gene sets enriched for mutations in pre- and post-chemotherapy tumors were very similar and reflected genes involved in the biological process of neurogenesis. Somatically mutated genes present in chemosensitive tumors included COL1A2, PRMD15, APOBEC3B, PALB2 and histone protein encoding genes, while BRCA1, ATR, ARID1A, XRCC3 and genes encoding for tubulin-associated proteins were present in the chemoresistant tumors. We also found that the mutational spectrum of post-chemotherapy tumors was more reflective of matching metastatic tumor biopsies than pre-chemotherapy samples. These findings support a portrait of modest ongoing genomic instability with respect to single-nucleotide variants induced by or selected for by chemotherapy in TNBCs.

p53 immunohistochemistry in endometrial cancer: clinical and molecular correlates in the PORTEC-3 trial

Standard molecular classification of endometrial cancers (EC) is now endorsed by the WHO and identifies p53-abnormal (p53abn) EC as the subgroup with the poorest prognosis and the most likely to benefit from adjuvant chemo(radio)therapy. P53abn EC are POLE wildtype, mismatch repair proficient and show abnormal immunohistochemical (IHC) staining for p53. Correct interpretation of routinely performed p53 IHC has therefore become of paramount importance. We aimed to comprehensively investigate abnormal p53 IHC patterns and their relation to clinicopathological and molecular features. Tumor material of 411 molecularly classified high-risk EC from consenting patients from the PORTEC-3 clinical trial were collected. p53 IHC was successful in 408 EC and was considered abnormal when the tumor showed a mutant expression pattern (including subclonal): overexpression, null or cytoplasmic. The presence of pathogenic mutations was determined by next generation sequencing (NGS). Abnormal p53 expression was observed in 131/408 (32%) tumors. The most common abnormal p53 IHC pattern was overexpression (n = 89, 68%), followed by null (n = 12, 9%) and cytoplasmic (n = 3, 2%). Subclonal abnormal p53 staining was observed in 27 cases (21%), which was frequently but not exclusively, associated with POLE mutations and/or MMRd (n = 22/27; p < 0.001). Agreement between p53 IHC and TP53 NGS was observed in 90.7%, resulting in a sensitivity and specificity of 83.6% and 94.3%, respectively. Excluding POLEmut and MMRd EC, as per the WHO-endorsed algorithm, increased the accuracy to 94.5% with sensitivity and specificity of 95.0% and 94.1%, respectively. Our data shows that awareness of the abnormal p53 IHC patterns are prerequisites for correct EC molecular classification. Subclonal abnormal p53 expression is a strong indicator for POLEmut and/or MMRd EC. No significant differences in clinical outcomes were observed among the abnormal p53 IHC patterns. Our data support use of the WHO-endorsed algorithm and combining the different abnormal p53 IHC patterns into one diagnostic entity (p53abn EC).

Isotypic analysis of anti-p53 serum autoantibodies and p53 protein tissue phenotypes in colorectal cancer

The presence of IgA- and IgM-specific autoantibody (AAb) isotypes and their relationship to p53 tissue expression patterns are not well understood. This study aims to investigate the clinical utility of the anti-p53 AAb isotypes and tissue positivity in colorectal cancer (CRC). We analysed anti-p53 IgG, IgM, and IgA AAbs in sera of 99 CRC patients and 99 non-cancer control subjects. Corresponding tissue expression of the p53 protein was evaluated by immunohistochemistry (IHC). Anti-p53 AAbs of the IgG isotype were present in the sera of 21 out of 99 patients (21%), while IgM AAbs were observed in 9 (9%) and IgA in 2 (2%) CRC patients. Anti-p53 AAbs of all three isotypes were generally associated with IHC staining indicative of mutated TP53. Seropositive anti-p53 IgM cases in the absence of anti-p53 IgG were linked to wild-type p53. Anti-p53 IgA in the absence of IgG AAbs was detected in two non-cancer controls indicating a potential p53 epitope mimicry. Although seropositivity was not associated with patient survival (P = 0.650), mutant-pattern p53 tissue expression was associated with reduced 5-year overall survival (P = 0.032), however, it was not an independent prognostic marker (Multivariate Cox regression, P = 0.193). In conclusion, immunoglobulin isotyping revealed that anti-p53 IgM and IgA AAbs were predominantly concurrent with anti-p53 serum IgG and the mutant-pattern p53 tissue phenotype. IgM and IgA seropositive cases in absence of anti-p53 IgG were linked to wild-type p53 tissue phenotype indicating early anti-p53 immune responses preceding isotype class-switch (IgM) or p53 antigen mimicry (IgA).

TP53 Mutation as a Prognostic and Predictive Marker in Sarcoma: Pooled Analysis of MOSCATO and ProfiLER Precision Medicine Trials

(1) Background: locally resected high-grade sarcomas relapse in 40% of cases. There is no prognostic or predictive genomic marker for response to peri-operative chemotherapy. (2) Methods: MOSCATO and ProfiLER are pan-tumor prospective precision medicine trials for advanced tumors. Molecular analysis in both trials comprised targeted next-generation sequencing and comparative genomic hybridization array. We investigated if molecular alterations identified in these trials in sarcomas were associated with disease-free survival (DFS) and response to anthracyclines. (3) Results: this analysis included 215 sarcomas, amongst which 53 leiomyosarcomas, 27 rhabdomyosarcomas, 20 undifferentiated pleomorphic sarcomas, and 17 liposarcomas. The most frequently altered gene was TP53 (46 mutations and eight deletions). There were 149 surgically resected localized sarcomas. Median DFS in TP53 wild type (WT), deleted, and mutated sarcomas was 16, 10, and 10 months, respectively (p = 0.028; deletions: HR = 1.55; 95% CI = 0.75-3.19; mutations: HR = 1.70; 95%CI = 1.13-2.64). In multivariate analysis, TP53 mutations remained associated with shorter DFS (p = 0.027; HR = 2.30; 95%CI = 1.10-4.82). There were 161 localized and advanced sarcomas evaluable for response to anthracyclines. Objective response rates were 35% and 55% in TP53 WT and mutated sarcomas, respectively (OR = 2.24; 95%CI = 1.01-5.03; p = 0.05). In multivariate analysis, TP53 mutations remained associated with increased response (OR = 3.24; 95%CI = 1.30-8.45; p = 0.01). (4) Conclusions: TP53 mutations are associated with shorter DFS and increased response to anthracyclines. Post-validation, these findings could assist in decision-making for peri-operative treatments.

Prognostic Value of the TP53 Mutation Location in Metastatic Breast Cancer as Detected by Next-Generation Sequencing

Purpose

The status of TP53 mutations was measured in cell-free DNA from patients with metastatic breast cancer (MBC) to investigate disease characteristics and the prognostic role of different locations of the TP53 mutation site.

Patients and Methods

Blood samples were taken from a total of 187 patients diagnosed with MBC who were treated at the Department of Breast Oncology, Peking University Cancer Hospital between January 2013 and March 2020. Next-generation sequencing was used to investigate the TP53 mutation spectra of circulating free DNA in these blood samples.

Results

Among the 187 MBC patients, TP53-mutated patients had a significantly shorter median disease-free survival (DFS) and overall survival (OS) compared with TP53 wild-type patients (P=0.001 and P=0.006, respectively). Additionally, in hormone receptor positive/HER2 negative (HR+/HER2-) and triple negative (TNBC) cohorts, TP53-mutated patients had a significantly shorter median DFS than TP53 wild-type patients (P=0.038 and P=0.023, respectively). The 79 patients with TP53 mutations carried 87 somatic TP53 mutations, of which most (77.0%) mapped to the DNA-binding domain (DBD) of the protein encoded by TP53 exons 5–8. In patients with TP53 mutations, those occurring in the non-DBD had a significantly shorter median DFS and OS than TP53 wild type (P<0.001 and P=0.001, respectively). Additionally, patients with non-missense mutations in the DBD had a significantly shorter median DFS and OS than TP53 wild-type patients (P=0.001 and P<0.001, respectively). TP53-mutated patients had a significantly shorter DFS than TP53 wild-type patients in the adjuvant endocrine therapy sensitive group (P=0.008), but differences in the endocrine therapy resistant group were not significant.

Conclusion

TP53-mutated MBC patients had a significantly worse outcome than TP53 wild-type patients especially those in HR+/HER2– and TNBC cohorts. Of TP53-mutated patients, those with non-missense mutations in the DBD had worse breast cancer-related survival. TP53 mutations were also associated with endocrine resistance.

Triple-Negative Breast Cancer: Assessing the Role of Immunohistochemical Biomarkers on Neoadjuvant Treatment

OBJECTIVE

This study aimed to investigate the influence of immunohistochemical (IHC) biomarkers in the response to neoadjuvant chemotherapy (NACT) and survival outcomes in the subset of locally advanced triple-negative breast cancer (TNBC).

MATERIALS AND METHODS

The epidermal growth factor receptor (EGFR), androgen receptor (AR), cytokeratins (CK5/6, CK14 and CK17), Ki67 and p53 immunohistochemistry were evaluated on 171 cases of TNBC submitted to NACT and subsequently to surgery. Intensity and percentage of the expression of these biomarkers were combined to formulate a specific score, that was correlated with prognostic features and assessed for survival outcomes.

RESULTS

Most patients had advanced clinical-stage tumors (stage III: 83.6%; cT3/T4: 85.9%; cN1-3: 71.3%). The predominant histological subtype was high-grade (67.3%) and invasive ductal carcinoma (93.6%). The residual cancer burden (RCB) 0-1 corresponded to 28.7% of cases and low-risk lymph node ratio (LNR) represented 77.2%. High Ki67 expression only showed a significant correlation with grade 3 tumors (p = 0.0157). CK5/6 was observed in 16% (27/169), CK14 was positive in 10.1% (17/169), CK17 in 91.1% (153/168), p53 in 52.6% (70/133), EGFR in 92.9% (157/169 cases), AR in 13% (22/169) and Ki67 index was scored ≥40% in 57.9% (95/165). No IHC biomarker significantly impacted response or survival. Regarding the analysis of the outcomes of event-free survival (EFS) and overall survival (OS), clinical stage (p = 0.014 and p = 0.042, respectively), RCB (p < 0.0001 and p <0.0001, respectively) and LNR (p <0.0001 and p <0.0001, respectively) showed significant association.

CONCLUSION

No IHC biomarker evaluated showed a significant association with a response or survival outcomes in TNBC patients. Clinical stage, LNR and RCB stood out for strongly influencing survival.

p53 and BLC2 Immunohistochemical Expression Across Molecular Subtypes in 1099 Early Breast Cancer Patients With Long-Term Follow-up: An Observational Study

INTRODUCTION

p53 and antiapoptotic B-cell leukemia/lymphoma 2 (BLC2) have been proposed as prognostic markers for early breast cancer (BC), although their relationship with conventional parameters and patient prognosis, as well as their distribution within the molecular BC subtypes remains uncertain.

PATIENTS AND METHODS

In this observational study, we analyzed the immunohistochemical expression of p53 and BLC2 in 1099 early BC patients surgically treated between 2000 and 2006 and followed for at least 5 years, also considering their association with pathologic factors and molecular subtypes, as well as their influence on disease-free survival.

RESULTS

p53 and BLC2 are distributed differently across molecular subtypes (P < .0001); in particular, p53 positivity and BLC2 negativity seems to be associated with more aggressive conventional tumor phenotypes. Moreover, BLC2 negativity seems to be a significant discriminating factor for disease-free survival (P = .003) according to Kaplan-Meier analysis, while p53 seems to have no discriminating effect. Among patients with discordant p53/BLC2 phenotype, the combination p53⁺BLC2^- seems to be associated with the worst outcomes (P = .007) and significantly influenced the clinical course of node-negative patients treated only with hormone therapy (P = .004).

CONCLUSION

These two biomarkers, in addition to conventional pathologic factors and molecular subtype, could help define the risk and outcome of BC.

TP53 Mutations and Outcomes in Breast Cancer: Reading beyond the Headlines

TP53 is the most frequently mutated gene in breast cancer, but its role in survival is confounded by different studies concluding that TP53 mutations are associated with negative, neutral, or positive outcomes. Closer examination showed that many studies were limited by factors such as imprecise methods to detect TP53 mutations and small cohorts that combined patients treated with drugs having very different mechanisms of action. When only studies of patients receiving the same treatment(s) were compared, they tended to agree. These analyses reveal a role for TP53 in response to different treatments as complex as its different biological activities. We discuss studies that have assessed the role of TP53 mutations in breast cancer treatment and limitations in interpreting reported results.

Correlations between CD4+ FoxP3+ Treg and expression of FoxM1 and Ki-67 in gastric cancer patients

AIMS

In this study, we intended to analyze the clinical significance of CD4⁺ FoxP3⁺ Tregs in gastric cancer patients and investigate the relationship between the proportion of CD4⁺ FoxP3⁺ Tregs in the peripheral blood and the expression of FoxM1 and Ki-67 in gastric cancer tissues.

METHODS

Flow cytometry was used to measure the CD4⁺ FoxP3⁺ Tregs level in peripheral blood from 70 gastric cancer patients one day before gastrectomy and D2 lymph node dissection. Immunohistochemistry staining was used to detect the expression of FoxM1 and Ki-67 in gastric cancer tissues. Data on clinico-pathological features and correlation between Tregs and the expression of FoxM1 and Ki-67 were then analyzed.

RESULTS

The average proportion of CD4⁺ FoxP3⁺ Tregs in gastric cancer patients' peripheral blood before surgery was 10.12 ± 2.85%, which was significantly higher in patients with late AJCC stage (P = 0.029) or lymph node metastasis (P = 0.003) compared to patients at earlier AJCC stage or without lymph node metastasis. The levels of CD4⁺ FoxP3⁺ Treg cells was positively correlated with the protein expression of FoxM1 (P = 0.003) and Ki-67 (P = 0.001), respectively.

CONCLUSION

These results suggest the level of CD4⁺ FoxP3⁺ Treg cells in peripheral blood has clinical significance in gastric cancer patients. The overexpression of FoxM1 and Ki-67 may relate to immunosuppression in gastric cancer.

Pathogenic mutations and overall survival in 3,084 patients with cancer: the Hellenic Cooperative Oncology Group Precision Medicine Initiative

Background: We evaluated the association between pathogenic mutations and overall survival (OS) in patients with cancer referred to Hellenic Cooperative Oncology Group–affiliated Departments.

Patients and methods: Patients referred from 12/1980 to 1/2017 had molecular testing (for research) of archival tumor tissue collected at the time of first diagnosis (non-metastatic, 81%; metastatic, 19%). Tumor-specific gene panels (16-101 genes) were used to identify pathogenic mutations in clinically relevant genes. NGS genotyping was performed at the Laboratory of Molecular Oncology, Aristotle University of Thessaloniki. Annotation of mutations was performed at MD Anderson Cancer Center.

Results: We analyzed 3,084 patients (median age, 57 years; men, 22%) with sequencing data. Overall, 1,775 (58% of 3,084) patients had pathogenic mutations. The median follow-up was 7.52 years (95% CI, 7.39-7.61). In patients with non-metastatic tumors, after stratification by tumor type, increasing age, higher grade, and histology other than adenocarcinoma were associated with shorter OS. OS was also shorter in patients with pathogenic TP53 (HR=1.36; p<0.001), MLL3 (HR=1.64; p=0.005), and BRCA1 (HR=1.46; p=0.047) mutations compared to wild-type genes. In multivariate analyses, independent prognostic factors predicting shorter OS were pathogenic mutations in TP53 (HR=1.37, p=0.002) and MLL3 (HR=1.50, p=0.027); increasing age (HR=1.02, p<0.001); and increasing grade (HR=1.46, p<0.001). In patients with metastatic cancer, older age and higher grade were associated with shorter OS and maintained their independent prognostic significance (increasing age, HR=1.03, p<0.001 and higher grade, HR=1.73, p<0.001).

Conclusions: Analysis of molecular data reveals prognostic biomarkers, regardless of tissue or organ of origin to improve patient management.

Adjuvant regional nodal irradiation did not improve outcomes in T1-2N1 breast cancer after breast-conserving surgery: A propensity score matching analysis of BIG02/98 and BCIRG005 trials

Aim

To determine whether the addition of regional nodal irradiation (RNI) to whole-breast irradiation (WBI) would improve outcomes over WBI alone in T1-2N1 breast cancer after breast-conserving surgery (BCS) and adjuvant systematic therapy.

Methods

Data were obtained from two randomized controlled trials (NCT00174655 and NCT00312208). Univariate and multivariate Cox-regression analysis were performed to investigate predictors for overall survival and disease-free survival. A 1:1 propensity score matching (PSM) analysis was applied to eliminate selection bias.

Results

With median follow-up 80 months (range: 3–155 months), the 5-year local regional recurrence in the WBI group was 2% vs. 5% (p = 0.28) in the WBI + supraclavicular radiotherapy, and the rate of 5-year distant metastasis in the WBI group was 7% vs. 13% in the WBI + supraclavicular radiotherapy (p = 0.0748); In addition, the 5-year local regional recurrence in the WBI group was 3% vs. 9% (p = 0.19) in the WBI + internal mammary irradiation (IMI); However, the rate of 5-year distant metastasis in the in the WBI group was significantly lower than that in the WBI + IMI (8% vs. 24%, p = 0.036). After PSM, cox-regression analysis indicated that neither RNI nor IMI in combination with WBI in T1-2N1 breast cancer was associated with an improved overall survival and disease-free survival when compared to WBI alone.

Conclusion

The addition of RNI to WBI in T1-2N1 breast cancer after BCS and adjuvant systematic therapy did not improve outcomes in comparison with WBI alone. Further studies are still needed to identify patients who would most benefit from RNI in this patient population.

•

The addition of RNI to WBI in unselected T1-2N1 breast cancer after BCS and adjuvant systematic therapy does not significantly improve outcomes in comparison with WBI alone.

•

Early stage (pT1-2N1) breast cancer after BCS represents a diverse population.

•

An individualized risk analysis based on clinical-genomic models is recommended to identify patients who would benefits or omit from RNI in further prospective studies.

Association between FGFR1 copy numbers, MAP3K1 mutations, and survival in axillary node-positive, hormone receptor-positive, and HER2-negative early breast cancer in the PACS04 and METABRIC studies

PURPOSE

Hormone receptor-positive (HR+) and human epidermal growth factor receptor 2 negative (HER2-) early breast cancer (BC) is the most prevalent BC subtype with substantial biological heterogeneity. Although clinicopathological (CP) characteristics have a clear prognostic value, additional biomarkers could refine survival prediction and guide treatment decision.

METHODS

Copy number aberrations and somatic driver mutations were obtained with OncoScan CGH array and sequencing of 36 genes on HR+/HER2- node-positive early BC patients treated with chemotherapy from the PACS04 trial. We built a two-gene genomic score (GS) associated with distant disease-free survival (DDFS), whose prognostic value was assessed on the external METABRIC data (n = 1413) using overall survival (OS) and breast cancer-specific survival (BCSS).

RESULTS

In the PACS04 trial (n = 327), the median follow-up for DDFS (65 events) was 9.6 years. FGFR1 amplifications ([Formula: see text] = 2.44, 95% CI [1.25; 4.76], p = 0.009) and MAP3K1 mutations ([Formula: see text] = 0.10, [0.01; 0.78], p = 0.03) were associated with DDFS beyond CP characteristics. A prognostic GS combining FGFR1 amplifications and MAP3K1 mutations added more information to CP model ([Formula: see text] = 12.97, [Formula: see text] < 0.001 and [Formula: see text] = 11.52, [Formula: see text] < 0.001). In the METABRIC study (n = 1413), FGFR1 amplifications ([Formula: see text] = 2.00 [1.40; 2.87], p < 0.001) and MAP3K1 mutations ([Formula: see text] = 0.58 [0.41; 0.83], p = 0.003) were significantly associated with BCSS beyond CP characteristics. The prognostic GS added significant prognostic information to CP model ([Formula: see text] = 15.39, [Formula: see text] < 0.001 and [Formula: see text] = 5.62, [Formula: see text] = 0.02).

CONCLUSION

In axillary node-positive, HR+, and HER2- early BC, amplifications of FGFR1 gene were strongly associated with increased risk for distant disease, while mutations of MAP3K1 gene were significantly associated with decreased risk.

Incidence and predictors of 1-year mortality among 9236 breast cancer patients referred for adjuvant chemotherapy

AIM

To evaluate the incidence and predictors of mortality in the first year following randomization among breast cancer patients recruited in five adjuvant chemotherapy clinical trials.

METHODS

This is a pooled analysis of 9236 patients from five clinical trials. Univariate and multivariate logistic regression analyses were conducted to evaluate the impact of relevant clinicopathological factors on early mortality.

RESULTS

Early death rates were 0.1% (11 patients) at 6 months and 0.8% (70 patients) at 1 year. Patients with a documented relapse within 1 year have a higher risk of death within the first year (HR: 74.20, 95% CI: 42.28-130.22) in a multivariate Cox regression model. The following factors were predictive of 1-year mortality in multivariate logistic regression analysis: higher T-stage (p = 0.001), higher N-stage (p = 0.004) and negative hormone receptor status (p < 0.0001).

CONCLUSION

Six-month and 1-year mortality rates are low among breast cancer patients referred for adjuvant chemotherapy within a clinical trial.

Differences in prognosis and efficacy of chemotherapy by p53 expression in triple-negative breast cancer

PURPOSE

TP53 mutation is the most common mutation in breast cancer, and it is considered a target marker of triple-negative breast cancer (TNBC). We investigated whether expression of p53 detected by immunochemical staining predicts the chemotherapy response of TNBC.

METHODS

A total of 11,393 TNBC patients who had between stage I and stage III enrolled in the Korean Breast Cancer Society Registry database from January 1, 2000 to December 31, 2015. There were 6,331 'p53-positive (+) TNBC' patients and 5062 'p53-negative (-) TNBC' patients.

RESULTS

In univariate analysis, p53(+) TNBC had a worse prognosis than p53(-) TNBC in patients not receiving chemotherapy (P = 0.003). However, there was no difference in prognosis between p53(+) TNBC and p53(-) TNBC for patients receiving chemotherapy. In multivariate analysis adjusted for age and stage, the risk of p53(+) TNBC was 1.84 times higher than that of p53(-) TNBC in the non-chemotherapy group. However, there was no difference between p53(+) TNBC and p53(-) TNBC in patients receiving chemotherapy. In p53(+) TNBC, the risk was 0.6-fold lower when chemotherapy was administered than when chemotherapy was not administered. However, in p53(-) TNBC, there was no risk reduction effect by chemotherapy.

CONCLUSION

The prognosis of p53(+) TNBC has worse than p53(-) TNBC, but the risk for survival was significantly reduced with chemotherapy. It suggests that p53(+) TNBC would be more sensitive to chemotherapy than p53(-) TNBC.

Impact of postmastectomy radiotherapy on the outcomes of breast cancer patients with T1-2 N1 disease : An individual patient data analysis of three clinical trials

PURPOSE

To assess the impact of postmastectomy radiotherapy (PMRT) on overall survival and relapse-free survival among breast cancer patients with T1-T2 N1 disease who received standard adjuvant systemic therapy.

METHODS

This is an individual patient data pooled analysis of 1053 breast cancer patients referred for adjuvant therapy in three clinical trials (BIG 02/98, BCIRG001, and BCIRG005). Overall survival was assessed according to whether or not patients received adjuvant radiotherapy through Kaplan-Meier analysis. Univariate and multivariate analyses of predictors of overall and relapse-free survival were conducted through Cox regression analysis.

RESULTS

Locoregional relapse rates (after a median follow up of 116 months) were 5.6% among patients who received adjuvant radiotherapy vs. 6.6% among patients who did not receive adjuvant radiotherapy. Actuarial 5‑ and 10-year locoregional relapse-free survival rates were 94 and 93%, respectively, among patients who did not receive adjuvant radiotherapy versus 95 and 92% among patients who received adjuvant radiotherapy. The following factors were associated with worse overall survival in multivariate Cox regression analysis: age < 40 years (P < 0.0001), T2 stage (P = 0.004), higher lymph node ratio (P < 0.0001), and negative hormone receptor status (P < 0.0001). Likewise, the following factors were predictive of shorter locoregional relapse-free survival: age ≤ 40 (P < 0.0001), no PMRT (P = 0.034), fluorouracil/adriamycin/cyclophosphamide (FAC) chemotherapy (P = 0.001), and higher T stage (P = 0.002).

CONCLUSION

The current analysis does not show a beneficial impact of PMRT on overall or relapse-free survival among patients with T1-T2 N1 disease who received standard adjuvant systemic therapy. There is, however, evidence of improvement in locoregional relapse-free survival with PMRT. These findings need to be prospectively validated.

Impact of Regional Nodal Irradiation on the Outcomes of N1 Breast Cancer Patients Referred for Adjuvant Treatment: A Patient-Level Pooled Analysis of 2 Clinical Trials

PURPOSE

To evaluate the impact of regional nodal irradiation (RNI) among N1 operable breast cancer patients who underwent adequate axillary dissection and received adjuvant chemotherapy.

PATIENTS AND METHODS

This is a pooled analysis of 812 breast cancer patients referred for adjuvant systemic therapy in 2 prospective randomized studies: NCT00174655 (BIG 02/98) and NCT00312208 (BCIRG005). Overall survival was assessed according to whether patients received supraclavicular and/or internal mammary radiotherapy through Kaplan-Meier estimates. Univariate and multivariate analyses of variables affecting overall and relapse-free survival were performed through Cox regression analysis. Additionally, recurrence rates were analyzed according to regional irradiation patterns.

RESULTS

Regional relapse rates (after a median follow-up of 76 months) were 1.5% in both groups of patients who received or did not receive supraclavicular radiotherapy. The risk of regional recurrence was 0.7% in patients who received internal mammary node radiotherapy versus 1.6% in patients who did not receive internal mammary node radiotherapy. The following factors were associated with worse overall survival in multivariate Cox regression analysis: age < 40 years (P < .0001), > T1 stage (P = .003), and negative hormone receptor status (P = .002). Neither supraclavicular nor internal mammary radiotherapy was associated with improvement in overall or relapse-free survival in Cox regression analysis.

CONCLUSION

The current analysis does not endorse the routine use of supraclavicular or internal mammary radiotherapy among N1 operable breast cancer patients who have undergone adequate dissection of axillary lymph nodes and who have received standard adjuvant systemic therapy. Given the limited power and potential selection bias of the current analysis, further prospective studies are needed to tackle this research question.

Patterns of on-treatment cardiac adverse events within three clinical trials of adjuvant anthracycline-based chemotherapy

BACKGROUND

This study aims to assess the patterns of development of on-treatment cardiac side effects among patients with early breast cancer receiving anthracycline-based chemotherapy.

METHODS

This is a pooled analysis of patient-level data of patients with early-stage breast cancer who were recruited into three clinical trials to receive different adjuvant chemotherapy regimens. Univariable and multivariable analyses of factors predicting the development of on-treatment cardiac adverse events were conducted through logistic regression analysis. The following factors were evaluated in the univariable analysis: age, menopausal status, body mass index, T stage, and type of chemotherapy protocol.

RESULTS

Among the studied patients, 226 patients (6.7%) experienced 230 incidents of on-treatment cardiac toxicities. Cardiac ischemia was reported among 8 patients, cardiac dysfunction was reported among 19 patients, arrhythmias were reported in 161 patients and other non-specified forms of cardiac adverse events were reported in 42 patients. In univariable logistic regression, the following parameters were predictive of a higher probability of on-treatment cardiac adverse events (P < 0.05): higher age, higher body mass index and FAC chemotherapy protocol. When these factors were included in the multivariable logistic regression analysis, the following factors were predictive of a higher probability of cardiac adverse events: higher body mass index (P = 0.050) and FAC chemotherapy protocol (P = 0.001).

CONCLUSION

On-treatment cardiac events are not uncommon during adjuvant chemotherapy for early breast cancer. Higher dose of anthracyclines and higher body mass index are associated with a higher risk of on-treatment cardiac events.

Biallelic TP53 gain of function mutations in rapidly progressing solid tumors

Recent studies are discovering TP53 mutations with gain of function (GOF) properties that promote tumorigenesis via a variety of mechanisms. To our knowledge, all reported compound mutations are allelic. We identified two patients with biallelic GOF TP53 mutations in their tumors and a third with allelic compound variants. The correlation with p53 expression was also examined. Genomic DNA was extracted from formalin-fixed, paraffin-embedded tissue and mutational analysis was performed using Ion AmpliSeq™Cancer HotSpot Panel V2. Biallelic GOF mutations (p.R273H and p.R273C) were identified in a 19-year-old male with glioblastoma (allele frequencies 94% and 48%) and a 54-year-old with pT3 penile squamous cell carcinoma (allele frequencies 19% and 27%). Immunohistochemistry showed nuclear accumulation of p53. The third patient, a 62-year-old female with metastatic lung adenocarcinoma, had allelic p.P278S (GOF) and p.R283L (non-GOF) variants at frequencies of 61% but with null staining for p53. Germline testing for Patient 1 confirmed wildtype TP53. No other variants were discovered among the genes tested in these cases. All patients succumbed within two years of diagnosis despite aggressive treatment. In conclusion, implementation of TP53 mutation analysis in clinical practice may predict patient outcome, and inhibition of GOF p53 could represent an attractive target for therapy.

Mutant p53 in breast cancer: potential as a therapeutic target and biomarker

OBJECTIVE

The aim of this article is to discuss mutant p53 as a possible therapeutic target and biomarker for breast cancer.

RESULTS

TP53 (p53) is the most frequently mutated gene in invasive breast cancer. Although mutated in 30-35% of all cases, p53 is mutated in approximately 80% of triple-negative (TN) tumors (i.e., tumors negative for ER, PR, and HER2). Because of this high prevalence, mutated p53 is both a potential biomarker and therapeutic target for patients with breast cancer, especially for those with the TN subtype. Although several retrospective studies have investigated a potential prognostic and therapy predictive role for mutant p53 in breast cancer, the results to date are mixed. Thus, at present, mutant p53 cannot be recommended as a prognostic or therapy predictive biomarker in breast cancer. In contrast to the multiple reports on a potential biomarker role, few studies had until recently, investigated mutant p53 as a potential target for breast cancer treatment. In the last decade, however, several compounds have become available which can reactivate mutant p53 protein and convert it to a conformation with wild-type properties. Some of these compounds, especially PRIMA-1, APR-246 PK11007, and COTI-2, have been found to exhibit anticancer activity in preclinical models of breast cancer.

CONCLUSION

Since p53 is mutated in the vast majority of TN breast cancers, compounds such as APR-246, PK11007, and COTI-2 are potential treatments for patients with this subform of the disease. Further research is necessary to identify a potential biomarker role for mutant p53 in breast cancer.

Prognostic significance of CD117 expression and TP53 missense mutations in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is extremely aggressive and associated with poor prognosis. There are no known predictive or prognostic markers for TNBC. Inhibition of tumor protein P53 (TP53) has been demonstrated to increase the levels of cluster of differentiation 117 (CD117) in human colorectal cancer cells. However, the function of TP53 in the regulation of CD117 in TNBC has, to the best of our knowledge, not been reported. In the present study, the association between the expression of CD117 protein and TP53 mutations was investigated, and their prognostic value in patients with TNBC was assessed. A total of 58 TNBC and 48 non-TNBC breast cancer tissue samples were assessed for the expression of CD117, p53 and TP53 mutations. The marker of proliferation Ki-67 (MKI67) proliferation index and vascular invasion index (obtained by measuring D2-40 and CD34) was investigated via immunohistochemistry, and mutations in exons 4–8 of TP53 were measured using direct sequencing. Associations between CD117 and p53 levels or TP53 mutations and clinical parameters were statistically evaluated. The rates of CD117 or MKI67 positivity, CD117⁺/TP53 missense mutation⁺, TP53 missense mutations or recurrence were significantly higher in patients with TNBC than in patients with non-TNBC. In TNBC tissues, the presence of CD117 was associated with TP53 missense mutations (P=0.031), vascular invasion, recurrence and MKI67. CD117⁺/TP53 missense mutation⁺ also associated with vascular invasion, recurrence and MKI67. Under univariate analysis, MKI67, vascular invasion, CD117, CD117⁺/TP53 missense mutation⁺ and TP53 missense mutations were associated with the overall survival of patients with TNBC. Multivariate analysis revealed that vascular invasion and CD117⁺/TP53 missense mutation⁺ in primary tumors were independent prognostic factors in patients with TNBC. In conclusion, CD117⁺/TP53 missense mutation⁺ was associated with MKI67, vascular invasion and tumor recurrence in TNBC. The presence of CD117 and TP53 missense mutations together in the primary tumors was an independent prognostic factor for survival of patients with TNBC.

MicroRNA-related polymorphisms in apoptosis pathway genes are predictive of clinical outcome in patients with limited disease small cell lung cancer

We examined the impact of single nucleotide polymorphisms (SNPs) at miRNA binding sites in the 3'-UTRs of genes in the apoptosis pathway on the prognosis of patients with limited disease-small cell lung cancer (LD-SCLC). Twelve tagSNPs in seven genes were genotyped using blood samples from 146 LD-SCLC patients treated with chemoradiotherapy. Cox proportional hazard regression models and recursive partitioning analysis were performed to identify SNPs significantly associated with overall survival. Three SNPs, CASP8: rs1045494 (C > T), PIK3R1: rs3756668 (A > G) and CASP7: rs4353229 (T > C), were associated with longer overall survival in LD-SCLC patients after chemoradiotherapy. The adjusted hazard ratios (95% confidence intervals) were 0.480 (0.258-0.894), 0.405 (0.173-0.947) and 0.446 (0.247-0.802), respectively, and remained significant after multiple comparison correction. Moreover, subset analysis showed these SNPs were still predictive of overall survival in stage III patients. Recursive partitioning analysis enabled patients to be classified into three risk subgroups based on unfavorable genotype combinations of the rs1045494 and rs4353229 SNPs. These findings suggest miRNA-related polymorphisms in the apoptosis pathway may be useful biomarkers for selection of LD-SCLC patients likely to benefit from chemoradiotherapy.

Overexpression of p53 protein is a marker of poor prognosis in Mexican women with breast cancer

Breast cancer (BC) is a disease with different clinical, histological and molecular characteristics, frequently presenting mutated tumour-suppressing genes and oncogenes. P53 is a known tumour suppressor that is often mutated in BC; several mutations in p53 inhibit its role as a transcriptional repressor of several oncogenes. Topoisomerase 2α (TOP2α) is a gene target of p53, and it is also a known target for anthracyclines. The aim of the present study, was to analyse the genetic alterations of p53 and TOP2α genes and their levels of protein expression, as well as their association with survival in Mexican women with BC. A total of 102 biopsies were collected (tumour and adjacent tissues) from patients with BC. To identify point mutations and deletions in the p53 gene, the Sanger sequencing method was carried out. Deletions or amplifications for TOP2α gene were determined using quantitative polymerase chain reaction (qPCR). In addition, the expression of the TOP2α and p53 proteins was evaluated by western blotting. Furthermore, p53 protein expression was analysed by proximity ligation assay (PLA)-qPCR. Only 28.5% of the patients were found to have triple-negative breast cancer (TNBC); the average age at the time of diagnosis of these patients was 50 years, and Scarff-Bloom-Richardson (SBR) histological grade III (p=0.0089). No differences in point mutations or deletions in p53, and deletions or amplifications as well as protein expression level of TOP2α were observed between patients with TNBC and non-TNBC patients. However, patients with TNBC showed p53 protein overexpression as determined by PLA-qPCR and western blotting (p<0.0001). Furthermore, we found an association between TOP2α amplification and overexpression of its protein in patients with TNBC (p<0.0001). Concerning p53, overexpression resulted in a lower survival in patients with BC.

Constitutively activated ERK sensitizes cancer cells to doxorubicin: Involvement of p53-EGFR-ERK pathway

The tumour suppressor gene p53 is mutated in approximately 50% of the human cancers. p53 is involved in genotoxic stress-induced cellular responses. The role of EGFR and ERK in DNA-damage-induced apoptosis is well known. We investigated the involvement of activation of ERK signalling as a consequence of non-functional p53, in sensitivity of cells to doxorubicin. We performed cell survival assays in cancer cell lines with varying p53 status: MCF-7 (wild-type p53, WTp53), MDA MB-468 (mutant p53, MUTp53), H1299 (absence of p53, NULLp53) and an isogenic cell line MCF-7As (WTp53 abrogated). Our results indicate that enhanced chemosensitivity of cells lacking wild-type p53 function is because of elevated levels of EGFR which activates ERK. Additionally, we noted that independent of p53 status, pERK contributes to doxorubicin-induced cell death.

TP53-based interaction analysis identifies cis-eQTL variants for TP53BP2, FBXO28, and FAM53A that associate with survival and treatment outcome in breast cancer

TP53 overexpression is indicative of somatic TP53 mutations and associates with aggressive tumors and poor prognosis in breast cancer. We utilized a two-stage SNP association study to detect variants associated with breast cancer survival in a TP53-dependent manner. Initially, a genome-wide study (n = 575 cases) was conducted to discover candidate SNPs for genotyping and validation in the Breast Cancer Association Consortium (BCAC). The SNPs were then tested for interaction with tumor TP53 status (n = 4,610) and anthracycline treatment (n = 17,828). For SNPs interacting with anthracycline treatment, siRNA knockdown experiments were carried out to validate candidate genes.In the test for interaction between SNP genotype and TP53 status, we identified one locus, represented by rs10916264 (p(interaction) = 3.44 × 10-5; FDR-adjusted p = 0.0011) in estrogen receptor (ER) positive cases. The rs10916264 AA genotype associated with worse survival among cases with ER-positive, TP53-positive tumors (hazard ratio [HR] 2.36, 95% confidence interval [C.I] 1.45 - 3.82). This is a cis-eQTL locus for FBXO28 and TP53BP2; expression levels of these genes were associated with patient survival specifically in ER-positive, TP53-mutated tumors. Additionally, the SNP rs798755 was associated with survival in interaction with anthracycline treatment (p(interaction) = 9.57 × 10-5, FDR-adjusted p = 0.0130). RNAi-based depletion of a predicted regulatory target gene, FAM53A, indicated that this gene can modulate doxorubicin sensitivity in breast cancer cell lines.If confirmed in independent data sets, these results may be of clinical relevance in the development of prognostic and predictive marker panels for breast cancer.

Exome Sequencing Identifies Potentially Druggable Mutations in Nasopharyngeal Carcinoma

In this study, we first performed whole exome sequencing of DNA from 10 untreated and clinically annotated fresh frozen nasopharyngeal carcinoma (NPC) biopsies and matched bloods to identify somatically mutated genes that may be amenable to targeted therapeutic strategies. We identified a total of 323 mutations which were either non-synonymous (n = 238) or synonymous (n = 85). Furthermore, our analysis revealed genes in key cancer pathways (DNA repair, cell cycle regulation, apoptosis, immune response, lipid signaling) were mutated, of which those in the lipid-signaling pathway were the most enriched. We next extended our analysis on a prioritized sub-set of 37 mutated genes plus top 5 mutated cancer genes listed in COSMIC using a custom designed HaloPlex target enrichment panel with an additional 88 NPC samples. Our analysis identified 160 additional non-synonymous mutations in 37/42 genes in 66/88 samples. Of these, 99/160 mutations within potentially druggable pathways were further selected for validation. Sanger sequencing revealed that 77/99 variants were true positives, giving an accuracy of 78%. Taken together, our study indicated that ~72% (n = 71/98) of NPC samples harbored mutations in one of the four cancer pathways (EGFR-PI3K-Akt-mTOR, NOTCH, NF-κB, DNA repair) which may be potentially useful as predictive biomarkers of response to matched targeted therapies.

Over-using chemotherapy in the adjuvant setting

Avoidance of unnecessary or ineffective treatment should be one of the main goals in adjuvant breast oncology today. Unfortunately, both patients and doctors hunt for tiny statistical differences in survival curves. This search could not only lead to an oncological approach of unlimited addition that we will not be able to afford, but would also end inevitably in indeterminate overtreatment with substantial risks of unexpected toxic effects eating away whatever progress we might make. "Do not harm" remains the main principle in medicine. To be able to follow this rule, we need to better understand the biology of breast cancer. The mistake of "one treatment fits all" can only be changed when we critically review trial designs of adjuvant breast oncology. The risk of overtreatment is there and selection of precisely defined cohorts for phase 3 trials is necessary, despite pressure of scientific ambition, pragmatism, and demands of industry. The "add on" clinical trial design model accepts the inability to confirm that standard therapy is still necessary if a positive result from the addition of the new therapy is obtained. The same model can be applied to "extended" adjuvant treatments in breast cancer subtypes. Addition of "miraculin" to the standard of care should generate a new standard. Such trials that show a modest benefit on average at a population level take us a step away from refining care for the individual, and might support the use of multiple and costly interventions with potential short and long term side effects. It is essential to escalate treatment when necessary and to de-escalate when un-necessary.

Somatic TP53 Mutations in the Era of Genome Sequencing

Amid the complexity of genetic alterations in human cancer, TP53 mutation appears as an almost invariant component, representing by far the most frequent genetic alteration overall. Compared with previous targeted sequencing studies, recent integrated genomics studies offer a less biased view of TP53 mutation patterns, revealing that >20% of mutations occur outside the DNA-binding domain. Among the 12 mutations representing each at least 1% of all mutations, five occur at residues directly involved in specific DNA binding, four affect the tertiary fold of the DNA-binding domain, and three are nonsense mutations, two of them in the carboxyl terminus. Significant mutations also occur in introns, affecting alternative splicing events or generating rearrangements (e.g., in intron 1 in sporadic osteosarcoma). In aggressive cancers, mutation is so common that it may not have prognostic value (all these cancers have impaired p53 function caused by mutation or by other mechanisms). In several other cancers, however, mutation makes a clear difference for prognostication, as, for example, in HER2-enriched breast cancers and in lung adenocarcinoma with EGFR mutations. Thus, the clinical significance of TP53 mutation is dependent on tumor subtype and context. Understanding the clinical impact of mutation will require integrating mutation-specific information (type, frequency, and predicted impact) with data on haplotypes and on loss of heterozygosity.

Diagnosis and Management of Hereditary Adrenal Cancer

Benign adrenocortical tumours (ACT) are relatively frequent lesions; on the contrary, adrenocortical carcinoma (ACC) is a rare and aggressive malignancy with unfavourable prognosis. Recent advances in the molecular understanding of adrenal cancer offer promise for better therapies in the future. Many of these advances stem from the molecular elucidation of genetic conditions predisposing to the development of ACC. Six main clinical syndromes have been described to be associated with hereditary adrenal cancer. In these conditions, genetic counselling plays an important role for the early detection and follow-up of the patients and the affected family members.

TP53 Mutational Analysis Enhances the Prognostic Accuracy of IHC4 and PAM50 Assays

IHC4 and PAM50 assays have been shown to provide additional prognostic information for patients with early breast cancer. We evaluated whether incorporating TP53 mutation analysis can further enhance their prognostic accuracy. We examined TP53 mutation and the IHC4 score in tumors of 605 patients diagnosed with stage I-III breast cancer at National Taiwan University Hospital (the NTUH cohort). We obtained information regarding TP53 mutation and PAM50 subtypes in 699 tumors from the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) cohort. We found that TP53 mutation was significantly associated with high-risk IHC4 group and with luminal B, HER2-enriched, and basal-like subtypes. Despite the strong associations, TP53 mutation independently predicted shorter relapse-free survival (hazard ratio [HR] = 1.63, P = 0.007) in the NTUH cohort and shorter breast cancer-specific survival (HR = 2.35, P = <0.001) in the METABRIC cohort. TP53 mutational analysis added significant prognostic information in addition to the IHC4 score (∆ LR-χ(2) = 8.61, P = 0.002) in the NTUH cohort and the PAM50 subtypes (∆ LR-χ(2) = 18.9, P = <0.001) in the METABRIC cohort. We conclude that incorporating TP53 mutation analysis can enhance the prognostic accuracy of the IHC4 and PAM50 assays.

Genotype and Haplotype Analyses of TP53 Gene in Breast Cancer Patients: Association with Risk and Clinical Outcomes

Variations in the TP53 gene have been suggested to play a role in many cancers, including breast. We previously observed an association between TP53 haplotypes based on four polymorphisms (rs17878362, rs1042522, rs12947788, and rs17884306) and the risk of colorectal and pancreatic cancer. Based on these results, in the present study, we have investigated the same polymorphisms and their haplotypes in 705 breast cancer cases and 611 healthy controls in relation to the disease risk, histopathological features of the tumor and clinical outcomes. In comparison to the most common haplotype A₁-G-C-G, all the other identified haplotypes were globally associated with a significantly decreased breast cancer risk (P = 0.006). In particular, the A₂-G-C-G haplotype was associated with a marked decreased risk of breast cancer when compared with the common haplotype (P = 0.0001). Moreover, rs1042522 in patients carrying the GC genotype and receiving only the anthracycline-based chemotherapy was associated with both overall and disease-free survival (recessive model for overall survival HR = 0.30 95% CI 0.11–0.80, P = 0.02 and for disease-free survival HR = 0.42 95% CI 0.21–0.84, P = 0.01). Present results suggest common genetic features in the susceptibility to breast and gastrointestinal cancers in respect to TP53 variations. In fact, similar haplotype distributions were observed for breast, colorectal, and pancreatic patients in associations with cancer risk. Rs1042522 polymorphism (even after applying the Dunn-Bonferroni correction for multiple testing) appears to be an independent prognostic marker in breast cancer patients.

Hereditary ovarian cancer: not only BRCA 1 and 2 genes

More than one-fifth of ovarian tumors have hereditary susceptibility and, in about 65-85% of these cases, the genetic abnormality is a germline mutation in BRCA genes. Nevertheless, several other suppressor genes and oncogenes have been associated with hereditary ovarian cancers, including the mismatch repair (MMR) genes in Lynch syndrome, the tumor suppressor gene, TP53, in the Li-Fraumeni syndrome, and several other genes involved in the double-strand breaks repair system, such as CHEK2, RAD51, BRIP1, and PALB2. The study of genetic discriminators and deregulated pathways involved in hereditary ovarian syndromes is relevant for the future development of molecular diagnostic strategies and targeted therapeutic approaches. The recent development and implementation of next-generation sequencing technologies have provided the opportunity to simultaneously analyze multiple cancer susceptibility genes, reduce the delay and costs, and optimize the molecular diagnosis of hereditary tumors. Particularly, the identification of mutations in ovarian cancer susceptibility genes in healthy women may result in a more personalized cancer risk management with tailored clinical and radiological surveillance, chemopreventive approaches, and/or prophylactic surgeries. On the other hand, for ovarian cancer patients, the identification of mutations may provide potential targets for biologic agents and guide treatment decision-making.

Adjuvant chemotherapy for early female breast cancer: a systematic review of the evidence for the 2014 Cancer Care Ontario systemic therapy guideline

BACKGROUND

The Program in Evidence-Based Care (pebc) of Cancer Care Ontario recently created an evidence-based consensus guideline on the systemic treatment of early breast cancer. The evidence for the guideline was compiled using a systematic review to answer the question "What is the optimal systemic therapy for patients with early-stage, operable breast cancer, when patient and disease factors are considered?" The question was addressed in three parts: cytotoxic chemotherapy, endocrine treatment, and human epidermal growth factor receptor 2 (her2)-directed therapy.

METHODS

For the systematic review, the medline and embase databases were searched for the period January 2008 to May 2014. The Standards and Guidelines Evidence directory of cancer guidelines and the Web sites of major oncology guideline organizations were also searched. The basic search terms were "breast cancer" and "systemic therapy" (chemotherapy, endocrine therapy, targeted agents, ovarian suppression), and results were limited to randomized controlled trials (rcts), guidelines, systematic reviews, and meta-analyses.

RESULTS

Several hundred documents that met the inclusion criteria were retrieved. The Early Breast Cancer Trialists' Collaborative Group meta-analyses encompassed many of the rcts found. Several additional studies that met the inclusion criteria were retained, as were other guidelines and systematic reviews. Chemotherapy was reviewed mainly in three classes: anti-metabolite-based regimens (for example, cyclophosphamide-methotrexate-5-fluorouracil), anthracyclines, and taxane-based regimens. In general, single-agent chemotherapy is not recommended for the adjuvant treatment of breast cancer in any patient population. Anthracycline-taxane-based polychemotherapy regimens are, overall, considered superior to earlier-generation regimens and have the most significant impact on patient survival outcomes. Regimens with varying anthracycline and taxane doses and schedules are options; in general, paclitaxel given every 3 weeks is inferior. Evidence does not support the use of bevacizumab in the adjuvant setting; other systemic therapy agents such as metformin and vaccines remain investigatory. Adjuvant bisphosphonates for menopausal women will be discussed in later work.

CONCLUSIONS

The results of this systematic review constitute a comprehensive compilation of the high-level evidence that is the basis for the 2014 pebc guideline on systemic therapy for early breast cancer. Use of cytotoxic chemotherapy is presented here; the results addressing endocrine therapy and her2-targeted treatment, and the final clinical practice recommendations, are published separately in this supplement.

RADIA: RNA and DNA integrated analysis for somatic mutation detection

The detection of somatic single nucleotide variants is a crucial component to the characterization of the cancer genome. Mutation calling algorithms thus far have focused on comparing the normal and tumor genomes from the same individual. In recent years, it has become routine for projects like The Cancer Genome Atlas (TCGA) to also sequence the tumor RNA. Here we present RADIA (RNA and DNA Integrated Analysis), a novel computational method combining the patient-matched normal and tumor DNA with the tumor RNA to detect somatic mutations. The inclusion of the RNA increases the power to detect somatic mutations, especially at low DNA allelic frequencies. By integrating an individual's DNA and RNA, we are able to detect mutations that would otherwise be missed by traditional algorithms that examine only the DNA. We demonstrate high sensitivity (84%) and very high precision (98% and 99%) for RADIA in patient data from endometrial carcinoma and lung adenocarcinoma from TCGA. Mutations with both high DNA and RNA read support have the highest validation rate of over 99%. We also introduce a simulation package that spikes in artificial mutations to patient data, rather than simulating sequencing data from a reference genome. We evaluate sensitivity on the simulation data and demonstrate our ability to rescue back mutations at low DNA allelic frequencies by including the RNA. Finally, we highlight mutations in important cancer genes that were rescued due to the incorporation of the RNA.

The prognostic significance of the aberrant extremes of p53 immunophenotypes in breast cancer

AIMS

The utility of p53 as a prognostic assay has been elusive. The aims of this study were to describe a novel, reproducible scoring system and assess the relationship between differential p53 immunohistochemistry (IHC) expression patterns, TP53 mutation status and patient outcomes in breast cancer.

METHODS AND RESULTS

Tissue microarrays were used to study p53 IHC expression patterns: expression was defined as extreme positive (EP), extreme negative (EN), and non-extreme (NE; intermediate patterns). Overall survival (OS) was used to define patient outcome. A representative subgroup (n = 30) showing the various p53 immunophenotypes was analysed for TP53 hotspot mutation status (exons 4-9). Extreme expression of any type occurred in 176 of 288 (61%) cases. As compared with NE expression, EP expression was significantly associated (P = 0.039) with poorer OS. In addition, as compared with NE expression, EN expression was associated (P = 0.059) with poorer OS. Combining cases showing either EP or EN expression better predicted OS than either pattern alone (P = 0.028). This combination immunophenotype was significant in univariate but not multivariate analysis. In subgroup analysis, six substitution exon mutations were detected, all corresponding to extreme IHC phenotypes. Five missense mutations corresponded to EP staining, and the nonsense mutation corresponded to EN staining. No mutations were detected in the NE group.

CONCLUSIONS

Patients with extreme p53 IHC expression have a worse OS than those with NE expression. Accounting for EN as well as EP expression improves the prognostic impact. Extreme expression positively correlates with nodal stage and histological grade, and negatively with hormone receptor status. Extreme expression may relate to specific mutational status.

Optimal adjuvant chemotherapy in breast cancer: selection of agents

Historically, the selection of the most effective adjuvant regimen for breast cancer patients was based on tumor size and nodal status but this approach took into account the stage only, without considering that the biology of the tumor matters as well, as breast cancer is a heterogeneous disease at the molecular level. In the present manuscript we will attempt to address the issue of selecting the most appropriate cytotoxic agents for adjuvant programs in the clinically and biologically distinct subgroups of endocrine responsive (luminal A and luminal B), HER2 positive and triple negative breast cancer patients.

Influence of mutation type on prognostic and predictive values of TP53 status in primary breast cancer patients

High rates of mutation in the TP53 tumor suppressor gene have been found in many human cancers, including breast tumors, making p53 one of the most studied proteins in oncology. However, the prognostic and predictive value of alterations in this gene remains ambiguous. To analyze the clinical value of somatic TP53 mutations, we collected clinical and molecular data on 210 women with primary breast cancer. We found significant associations of p53 mutations with tumor grade, metastasis, molecular subtype, Her2 status and inverse correlations with estrogen and progesterone receptor status. Cox proportional hazard analysis confirmed a strong prognostic value of p53 mutation for overall survival rate and highlighted significant interactions with lymph node involvement and tumor size. In relation to treatment options, TP53 mutations were associated with poor response to anthracyclines and radiotherapy. Categorization of TP53 mutations according to their type and location revealed that patients with nonsense mutation have the poorest prognosis in comparison with wild-type cases and other types of mutations in this gene. Classification of TP53 mutations with respect to the degree of disturbance of protein structure showed association of disruptive mutations with poorer patients' outcome in contrast to wild-type and non-disruptive mutations. In conclusion, the present study confirms p53 as a potential predictive and prognostic factor in oncology practice and highlights the growing evidence that distinct types of mutations have different clinical impacts.

TP53 mutation spectrum in breast cancer is subtype specific and has distinct prognostic relevance

PURPOSE

In breast cancer, the TP53 gene is frequently mutated and the mutations have been associated with poor prognosis. The prognostic impact of the different types of TP53 mutations across the different molecular subtypes is still poorly understood. Here, we characterize the spectrum and prognostic significance of TP53 mutations with respect to the PAM50 subtypes and integrative clusters (IC).

EXPERIMENTAL DESIGN

TP53 mutation status was obtained for 1,420 tumor samples from the METABRIC cohort by sequencing all coding exons using the Sanger method.

RESULTS

TP53 mutations were found in 28.3% of the tumors, conferring a worse overall and breast cancer-specific survival [HR = 2.03; 95% confidence interval (CI), 1.65-2.48, P < 0.001], and were also found to be an independent marker of poor prognosis in estrogen receptor-positive cases (HR = 1.86; 95% CI, 1.39-2.49, P < 0.001). The mutation spectrum of TP53 varied between the breast cancer subtypes, and individual alterations showed subtype-specific association. TP53 mutations were associated with increased mortality in patients with luminal B, HER2-enriched, and normal-like tumors, but not in patients with luminal A and basal-like tumors. Similar observations were made in ICs, where mutation associated with poorer outcome in IC1, IC4, and IC5. The combined effect of TP53 mutation, TP53 LOH, and MDM2 amplification on mortality was additive.

CONCLUSION

This study reveals that TP53 mutations have different clinical relevance in molecular subtypes of breast cancer, and suggests diverse roles for TP53 in the biology underlying breast cancer development.

Can biomarker assessment on circulating tumor cells help direct therapy in metastatic breast cancer?

Circulating tumor cell (CTC) count has prognostic significance in metastatic breast cancer, but the predictive utility of CTCs is uncertain. Molecular studies on CTCs have often been limited by a low number of CTCs isolated from a high background of leukocytes. Improved enrichment techniques are now allowing molecular characterisation of single CTCs, whereby molecular markers on single CTCs may provide a real-time assessment of tumor biomarker status from a blood test or “liquid biopsy”, potentially negating the need for a more invasive tissue biopsy. The predictive ability of CTC biomarker analysis has predominantly been assessed in relation to HER2, with variable and inconclusive results. Limited data exist for other biomarkers, such as the estrogen receptor. In addition to the need to define and validate the most accurate and reproducible method for CTC molecular analysis, the clinical relevance of biomarkers, including gain of HER2 on CTC after HER2 negative primary breast cancer, remains uncertain. This review summarises the currently available data relating to biomarker evaluation on CTCs and its role in directing management in metastatic breast cancer, discusses limitations, and outlines measures that may enable future development of this approach.

Unequal prognostic potentials of p53 gain-of-function mutations in human cancers associate with drug-metabolizing activity

Mutation of p53 is the most common genetic change in human cancer, causing complex effects including not only loss of wild-type function but also gain of novel oncogenic functions (GOF). It is increasingly likely that p53-hotspot mutations may confer different types and magnitudes of GOF, but the evidences are mainly supported by cellular and transgenic animal models. Here we combine large-scale cancer genomic data to characterize the prognostic significance of different p53 mutations in human cancers. Unexpectedly, only mutations on the Arg248 and Arg282 positions displayed significant association with shorter patient survival, but such association was not evident for other hotspot GOF mutations. Gene set enrichment analysis on these mutations revealed higher activity of drug-metabolizing enzymes, including the CYP3A4 cytochrome P450. Ectopic expression of p53 mutant R282W in H1299 and SaOS2 cells significantly upregulated CYP3A4 mRNA and protein levels, and cancer cell lines bearing mortality-associated p53 mutations display higher CYP3A4 expression and resistance to several CYP3A4-metabolized chemotherapeutic drugs. Our results suggest that p53 mutations have unequal GOF activities in human cancers, and future evaluation of p53 as a cancer biomarker should consider which mutation is present in the tumor, rather than having comparison between wild-type and mutant genotypes.

Clinicopathologic characteristics of brain tumors are associated with the presence and patterns of TP53 mutations: evidence from the IARC TP53 Database

Biological diversity in the development and progression of brain tumors may be based on the consequences of the nature of the TP53 mutation in the cancer sample. This study was designed to estimate the possible impact of the presence and spectrum of TP53 mutations on clinical variability of brain tumors using the IARC TP53 Database (R17). Somatic and germline mutation patterns differ in brain tumor carriers. The most frequent mutation in sporadic brain tumors is mutation R273C, which is relatively rare in grade 4 tumors compared with lower-grade tumors (p = 1.2 × 10(-5), OR 0.43, 95% CI 0.29-0.63). Mutations at all hot spots, DNA contact mutations, and mutations in the conserved regions of the TP53 gene are also more common in grade 1-3 tumors than in grade 4 tumors. The frequencies of missense mutations at hotspot codons and DNA contact mutations gradually decrease in all three age groups studied, indicating the role of these mutations in early-onset tumors. The role of TP53 somatic mutations in the development of brain tumors has been elucidated in the individual-participant meta-analysis that provided, for the first time, strong evidence that mean age at the onset of sporadic brain tumor is significantly lower in patients with mutated compared with wild-type TP53 in all groups stratified by tumor grade. The presence and patterns of TP53 mutations are associated mainly with the age at the onset and with the development of less malignant brain tumors. Malignant degeneration of brain tumors may depend on other genetic determinants.

Breast Cancer Biomarkers: Utility in Clinical Practice

Breast cancer is a heterogeneous disease. For the past decades, new technical tools have been developed for biomarkers at the DNA, RNA and protein levels to better understand the biology of breast cancer. This progress is essential to classify the disease into clinically relevant subtypes, which may lead to new therapeutic opportunities. Novel biomarker development is paramount to deliver personalized cancer therapies. Further, tumor evolution, being natural or under treatment pressure, should be monitored and "liquid biopsies" by detecting circulating tumor cells or circulating free tumor DNA in blood samples will become an important option. This paper reviews the new generation of biomarkers and the current evidence to demonstrate their analytical validity, clinical validity and clinical utility.

Tumor protein p53 (TP53) testing and Li-Fraumeni syndrome : current status of clinical applications and future directions

Prevalent as an acquired abnormality in cancer, the role of tumor protein p53 (TP53) as a germline mutation continues to evolve. The clinical impact of a germline TP53 mutation is often dramatic and affects the full life course, with a propensity to develop rare tumors in childhood and multiple common cancers of unexpectedly early onset in adulthood. In this article, we review the clinical relevance of germline mutations in the TP53 tumor suppressor gene to current healthcare practice, including the optimal ways to identify patients with Li-Fraumeni syndrome (LFS), to recognize the core cancers associated with LFS, and to develop strategies for early detection of LFS-associated tumors. Several TP53-targeted approaches to improve outcomes in LFS patients are also reviewed. A case report is used to highlight special TP53 testing dilemmas and unique challenges associated with genetic testing decisions in the current age of rapidly advancing genomic technologies.

Mapping genetic alterations causing chemoresistance in cancer: identifying the roads by tracking the drivers

Although new agents are implemented to cancer therapy, we lack fundamental understandings of the mechanisms of chemoresistance, the main obstacle to cure in cancer. Here we review clinical evidence linking molecular defects to drug resistance across different tumour forms and discuss contemporary experimental evidence exploring these mechanisms. Although evidence, in general, is sparse and fragmentary, merging knowledge links drug resistance, and also sensitivity, to defects in functional pathways having a key role in cell growth arrest or death and DNA repair. As these pathways may act in concert, there is a need to explore multiple mechanisms in parallel. Taking advantage of massive parallel sequencing and other novel high-throughput technologies and base research on biological hypotheses, we now have the possibility to characterize functional defects related to these key pathways and to design a new generation of studies identifying the mechanisms controlling resistance to different treatment regimens in different tumour forms.

Prognostic interaction between expression of p53 and estrogen receptor in patients with node-negative breast cancer: results from IBCSG Trials VIII and IX

INTRODUCTION

The prognostic significance of p53 protein expression in early breast cancer remains uncertain, with some but not all studies finding an association with poorer outcomes. Estrogen receptor (ER) expression is both a positive prognostic marker and predictive of response to endocrine therapies. The relationship between these biomarkers is unknown.

METHODS

We constructed tissue microarrays (TMAs) from available pathological material from 1113 patients participating in two randomized clinical trials comparing endocrine therapy alone versus chemo-endocrine therapy in node-negative breast cancer. Expression of p53 defined as >10% positive nuclei was analyzed together with prior immunohistochemical assays of ER performed at central pathological review of whole tumor sections.

RESULTS

ER was present (i.e. >1% positive tumor cell nuclei) in 80.1% (880/1092). p53 expression was significantly more frequent when ER was absent, 125/212 (59%) than when ER was present, 171/880 (19%), p <0.0001. A significant qualitative interaction was observed such that p53 expression was associated with better disease-free survival (DFS) and overall survival (OS) among patients whose tumors did not express ER, but worse DFS and OS among patients whose tumors expressed ER. The interaction remained significant after allowance for pathologic variables, and treatment. Similar effects were seen when luminal and non-luminal intrinsic subtypes were compared.

CONCLUSIONS

Interpretation of the prognostic significance of p53 expression requires knowledge of concurrent expression of ER. The reason for the interaction between p53 and ER is unknown but may reflect qualitatively different p53 mutations underlying the p53 expression in tumors with or without ER expression.

TRIAL REGISTRATION

Current Controlled Trials ACTRN12607000037404 (Trial VIII) and ACTRN12607000029493 (Trial IX).