Immunohistochemical expression of excision repair cross-complementing 1 (ERCC1) in non-small-cell lung cancer: implications for patient outcome

Biomarkers for efficacy of adjuvant chemotherapy following complete resection in NSCLC stages I-IIIA

Biomarkers may be useful when deciding which nonsmall cell lung cancer (NSCLC) patients may benefit from adjuvant chemotherapy following complete resection and which chemotherapeutic agents may be used preferably in individual patients in order to maximise survival.

A literature search covering the period from 2003 to May, 2014 was conducted using PubMed and the following search terms: “non-small cell lung cancer”, “NSCLC”, “adjuvant chemotherapy”, “randomized”, “randomised”, “biomarkers”, “prognostic”, “predictive”. This review focuses on current knowledge of biomarkers for prognosis or efficacy of adjuvant treatment following complete resection in stage I–IIIA NSCLC patients.

This review includes results on 18 different biomarkers and five gene profiles. A statistically significant prognostic impact was reported for: iNTR, TUBB3, RRM1, ERCC1, BRCA1, p53, MRP2, MSH2, TS, mucin, BAG-1, pERK1/2, pAkt-1, microRNA, TopIIA, 15-gene profile, 92-gene profile, 31-gene profile and 14-gene profile. A statistically significant predictive impact was reported for: ERCC1, p53, MSH2, p27, TUBB3, PARP1, ATM, 37-gene profile, 31-gene profile, 15-gene profile and 92-gene profile.

Uncertainties regarding the optimal analysis method and cut-off levels for the individual markers may blur the prognostic or predictive signals. None of the possible predictive markers have been validated in prospective trials. Thus, there are no biomarkers ready to use in an adjuvant setting in NSCLC.

Further investigation and validation is required to explore biomarkers in completely resected NSCLC stage I–IIIAhttp://ow.ly/M0leE

Cisplatin resistance and opportunities for precision medicine

Cisplatin is one of the most commonly used chemotherapy drugs, treating a wide range of cancer types. Unfortunately, many cancers initially respond to platinum treatment but when the tumor returns, drug resistance frequently occurs. Resistance to cisplatin is attributed to three molecular mechanisms: increased DNA repair, altered cellular accumulation, and increased drug inactivation. The use of precision medicine to make informed decisions on a patient's cisplatin resistance status and predicting the tumor response would allow the clinician to tailor the chemotherapy program based on the biology of the disease. In this review, key biomarkers of each molecular mechanism will be discussed along with the current clinical research. Additionally, known polymorphisms for each biomarker will be discussed in relation to their influence on cisplatin resistance.

Expression of hENTl and ERCC1 genes in tumor tissues non-small cell lung cancer

OBJECTIVE

To investigate the expression of hENTl and ERCC1 genes in tumor tissues non-small cell lung cancer (NSCLC).

METHODS

Fresh non-small lung cancer specimens were transplanted into nude mice. Twenty mice were randomized into two groups: experimental group receiving gemcitabine plus cisplatin and control group receiving 0.9% physiological saline. The expressions of hENTl and ERCC1 mRNA in tumor tissue were detected by real-time fluorescent quantitative PCR. The volume of tumor, the weight of nude mice and tumor volume were respectively measured and calculated 2-3 times per week. Tissue samples were collected from NSCLC mice treated with gemcitabine plus carboplatin.

RESULTS

The histological examination showed that many tumor cells were well preserved in nude mice. The rate of transplanted tumor cells was 86.7%. The concomitant treatment study showed that the rate of TV, RTV, T/C in GEM + DDP group was the lowest. LBP + DOC, DDP + DOC obviously influenced the body weight. Compared with NS group, DDP group, GEM group, the survival period and the level of hENTl of DDP+GEM group increased obviously, the level of ERCC1 decreased significantly (P<0.05).

CONCLUSIONS

The expression of hENT1 and ERCC1 genes in tumor tissues were closely correlated with the response to chemotherapy and prognosis of patients with NSCLC treated with gemcitabine plus cisplatin.

Customizing chemotherapy in thoracic malignancies based on ERCC1 expression

SUMMARY Platinum-based chemotherapy regimens using cisplatin or carboplatin are the cornerstones of treatment for advanced non-small-cell lung cancer (NSCLC), small-cell lung cancer and malignant pleural mesothelioma. Despite being standard regimens of choice in the majority of patients without oncogene driver mutations, the activity obtained by individual patients varies considerably. Hence, biomarkers such as ERCC1 are needed to predict sensitivity to drugs, which has been explored as a predictor for platinum sensitivity in thoracic malignancies, mostly in the case of NSCLC. ERCC1 may be measured by mRNA activity; however, most studies have examined protein expression via immunohistochemistry. High ERCC1 expression has been a good prognostic factor in resected NSCLC patients who are not receiving chemotherapy, while it has been an adverse predictor for the effect of cisplatin or carboplatin. The latter has also been shown in malignant pleural mesothelioma. Heterogeneous distribution of ERCC1 within tumors may be a source of discordance in the results obtained in various studies. Adding to the discordance may be the fact that there are four isoforms of ERCC1 and seemingly only one of these accounts for cisplatin sensitivity. It is possible that the antibodies used may be equally specific for the same isoforms, which contributes to the heterogeneity of results, in addition to the contribution from immunohistochemistry cutoff levels. Robust evidence in support of the use of ERCC1 to select treatment on an individual patient basis is lacking, and such results from ongoing trials are eagerly awaited in order to improve the possibilities for individualized chemotherapy with improved outcomes.