Gender-related differences in pathological and clinical tumor response based on immunohistochemical proteins expression in rectal cancer patients treated with short course of preoperative radiotherapy

Gender oncology: recommendations and consensus of the Italian Association of Medical Oncology (AIOM)

BACKGROUND

Following the development of gender medicine in the past 20 years, more recently in the field of oncology an increasing amount of evidence suggests gender differences in the epidemiology of cancers, as well as in the response and toxicity associated with therapies. In a gender approach, critical issues related to sexual and gender minority (SGM) populations must also be considered.

MATERIALS AND METHODS

A working group of opinion leaders approved by the Italian Association of Medical Oncology (AIOM) has been set up with the aim of drafting a shared document on gender oncology. Through the 'consensus conference' method of the RAND/University of California Los Angeles (UCLA) variant, the members of the group evaluated statements partly from the scientific literature and partly produced by the experts themselves [good practice points (GPPs)], on the following topics: (i) Healthcare organisation, (ii) Therapy, (iii) Host factors, (iv) Cancer biology, and (v) Communication and social interventions. Finally, in support of each specific topic, they considered it appropriate to present some successful case studies.

RESULTS

A total of 42 articles met the inclusion criteria, from which 50 recommendations were extracted. Panel participants were given the opportunity to propose additional evidence from studies not included in the research results, from which 32 statements were extracted, and to make recommendations not derived from literature such as GPPs, four of which have been developed. After an evaluation of relevance by the panel, it was found that 81 recommendations scored >7, while 3 scored between 4 and 6.9, and 2 scored below 4.

CONCLUSIONS

This consensus and the document compiled thereafter represent an attempt to evaluate the available scientific evidence on the theme of gender oncology and to suggest standard criteria both for scientific research and for the care of patients in clinical practice that should take gender into account.

Prognostic Biomarkers of Cell Proliferation in Colorectal Cancer (CRC): From Immunohistochemistry to Molecular Biology Techniques

Colorectal cancer (CRC) is one of the most common and severe malignancies worldwide. Recent advances in diagnostic methods allow for more accurate identification and detection of several molecular biomarkers associated with this cancer. Nonetheless, non-invasive and effective prognostic and predictive testing in CRC patients remains challenging. Classical prognostic genetic markers comprise mutations in several genes (e.g., APC, KRAS/BRAF, TGF-β, and TP53). Furthermore, CIN and MSI serve as chromosomal markers, while epigenetic markers include CIMP and many other candidates such as SERP, p14, p16, LINE-1, and RASSF1A. The number of proliferation-related long non-coding RNAs (e.g., SNHG1, SNHG6, MALAT-1, CRNDE) and microRNAs (e.g., miR-20a, miR-21, miR-143, miR-145, miR-181a/b) that could serve as potential CRC markers has also steadily increased in recent years. Among the immunohistochemical (IHC) proliferative markers, the prognostic value regarding the patients' overall survival (OS) or disease-free survival (DFS) has been confirmed for thymidylate synthase (TS), cyclin B1, cyclin D1, proliferating cell nuclear antigen (PCNA), and Ki-67. In most cases, the overexpression of these markers in tissues was related to worse OS and DFS. However, slowly proliferating cells should also be considered in CRC therapy (especially radiotherapy) as they could represent a reservoir from which cells are recruited to replenish the rapidly proliferating population in response to cell-damaging factors. Considering the above, the aim of this article is to review the most common proliferative markers assessed using various methods including IHC and selected molecular biology techniques (e.g., qRT-PCR, in situ hybridization, RNA/DNA sequencing, next-generation sequencing) as prognostic and predictive markers in CRC.

The prevalence of HPV infection in rectal cancer - Report from South - Central Poland (Cracow region)

Some studies suggest that HPV infection may be important carcinogenic factor in development of some part of colorectal cancers. However, in the worldwide literature concerning this type of tumours, the great variability in HPV frequency is noticed. In Poland, the incidence of HPV infection in colorectal cancers was examined in five studies so far and their results are also conflicting. Therefore, the aim of the present study was to assess the HPV presence in the group of 120 patients with adenocarcinomas of rectum. HPV infection was assessed on the basis of DNA extracted from collected formalin fixed paraffin embedded tumour specimens. Viral presence was evaluated using two PCR based methods: nested PCR and quantitative PCR (qPCR) with primers specific for HPV16. All HPV positive samples were subjected to virus genotyping using AmoyDx^® Human papillomavirus (HPV) Genotyping Detection Kit and P16 immunostaining. Among 120 evaluated colorectal tumours, HPV DNA was detected in 2 cancers (1.67%) by nested PCR and in 2 (1.67%) tumours by qPCR, including 1 sample diagnosed as HPV positive on the basis of both PCR variants. Two HPV positive cancers had HPV16 infection and other one HPV18. All three tumours with positivity of HPV DNA were P16 negative. In south - central Poland, HPV infection in rectal cancers probably has not influence on rectal carcinogenesis.

Positive effect of single nucleotide RAD51 135G>C polymorphism and low Ku70 protein expression on female rectal cancer patients survival after preoperative radiotherapy

BACKGROUND/AIMS

This is a retrospective analysis of 103 patients having locally advanced rectal cancer who received short-course radiotherapy (SCRT). The objective of the study was to check whether a polymorphism in the RAD51 gene (135 G>C), Ku70 protein expression, and tumor microenvironment: proliferation rate measured by BrdUrdLI and Ki-67LI, hypoxia (glucose transporter-1 expression), P53 protein expression, and DNA ploidy can influence DNA repair capacity, the factors contributing to patient overall survival (OS) and the incidence of recurrences and metastases.

MATERIALS AND METHODS

RAD51 (135 G>C) polymorphism was evaluated using restriction fragment length polymorphism polymerase chain reaction, and proteins were identified using immunohistochemistry.

RESULTS

There were 3 (2.9%) tumors with RAD51 CC, 75 (72.8%) with GG, and 25 (24.3%) with GC genotypes. The median follow-up time was 63.1 months (range 2-120). Patients with CC genotype survived significantly longer than those with GG and GC genotypes and did not develop any recurrences or distant metastases. Female patients with Ku70 expression (<75.1) or RAD51CC genotype (impaired DNA damage repair and radiosensitive) had significantly longer OS (p=0.013) than those with Ku70>75.1 % or RAD51GG,GC (radioresistant phenotype) and male patients in the log-rank test. In multivariate analysis, positive prognostic factors for OS in the male patients were grade=1 and <17 days break in the treatment, whereas in the female subgroup, only radiosensitive phenotype (Ku70 <75.1% or RAD51CC genotype).

CONCLUSION

To the best of our knowledge, this is the first study to provide evidence for the positive effect of CC genotype of RAD51 or low Ku70 expression on OS in females with rectal cancer after SCRT.

Gender-related prognostic significance of clinical and biological tumor features in rectal cancer patients receiving short-course preoperative radiotherapy

AIM

To study the prognostic value of clinical and biological features of rectal cancer and potential gender differences in patients' overall survival (OS), local recurrence-free survival (RFS) and metastasis-free survival (MFS) after short-course preoperative radiotherapy (SCRT) with short or long interval between RT and surgery (break).

BACKGROUND

The length of the interval between RT and surgery in SCRT is debatable and gender-related differences in patients survival are not established yet.

MATERIALS AND METHODS

126 patients received SCRT with 5 Gy dose per fraction during 5 days, followed by radical surgery after short break ≤17 days, and a long break >17 days. Pretreatment tumor proliferation (bromodeoxyuridine labeling index, BrdUrdLI and S-phase fraction) was evaluated by flow cytometry and proteins: CD34, Ki-67, GLUT-1, Ku70, BCL-2, P53 expression was studied immunohistochemically.

RESULTS

The studied group included 84 men and 42 women. There were 33, 76, and 17 cTNM (AJCC) tumor stages I, II, III, respectively. The median follow-up time was 53.3 months (range 2-142 months). For the whole group Cox multivariate analysis revealed that tumor grade (G > 1), interval between RT and surgery >17 days, pTNM stage >1 and P53 positivity + BrdUrdLI > 7.9% were negative prognostic factors for OS. Tumor aneuploidy and MVD > 140.8 vessels/mm² were important for RFS. pTNM stage > 1 and P53 positivity combined with BrdUrdLI > 7.9% were risk predictors for MFS. Based on tumor biological features, gender-related difference in OS, RFS, and MFS were observed. In multivariate analysis, male patients age > 62 years and break >17 days only appeared to be significant for OS.

CONCLUSIONS

In male rectal patients treated with SCRT, breaks between RT and surgery >17 days should be avoided because they negatively influence patients' survival.

Gender-related significance of time interval between radiotherapy and surgery in hypofractionated preoperative radiotherapy for rectal cancer patients' survival

AIM AND BACKGROUND

An optimal break between radiotherapy (RT) and surgery in short-course of RT (SCRT) for locally advanced rectal cancer is not clearly established. The aim of the study was to investigate the influence of the break in the preoperative SCRT and overall treatment time (OTT) for locally advanced rectal cancer patients (whole group and male/female subgroups) on patients overall survival (OS), recurrence-free survival (RFS), metastasis-free survival (MFS).

MATERIALS AND METHODS

131 patients were treated with SCRT (5 Gy/5 days), followed by surgery 3-53 days later. Break was calculated as the time interval between the end of irradiation to surgery and OTT as time interval from the beginning of RT to surgery.

RESULTS

Mean break was 21.5 (range 3-53.0) days and mean OTT was 26.5 (range 7-58.0) days. In univariate analysis, a break longer than 15 days and OTT >23 days were negative prognostic factors for OS for all patients, and particularly for the male patients' subgroup. RFS was non-significantly higher (P = 0.066) for patients treated with a break ≤15 days and OTT ≤23 days (P = 0.099), irrespectively of patients' sex. Patients treated with a break longer than 15 days and OTT >23 days had non-significantly lower level of MFS than those treated with a shorter break (P = 0.269) and OTT ≤23 days (P = 0.498).

CONCLUSION

In SCRT, a break in the treatment longer than 15 days, especially in the male patients subgroup, should be avoided, because it negatively affects patients' survival.

Gender bias in individual radiosensitivity and the association with genetic polymorphic variations

PURPOSE

To assess the extent of variation in radiosensitivity between individuals, gender-related dissimilarity and impact on the association with single nucleotide polymorphisms (SNPs).

MATERIALS AND METHODS

Survival curves of 152 fibroblast cell strains derived from both gender were generated. Individual radiosensitivity was characterized by the surviving fraction at 2Gy (SF2). SNPs in 10 radiation responsive genes were genotyped by direct sequencing.

RESULTS

The wide variation in SF2 (0.12-0.50; mean=0.33) was significantly associated with 3 SNPs: TP53 G72C (P=0.007), XRCC1 G399A (P=0.002) and ATM G1853A (P=0.01). Females and males differed significantly in radiosensitivity (P=0.004) that impacted genetic association where only XRCC1 remained significant in both gender (P<0.05). Meanwhile, discordant association was observed for TP53 that was significant in females (P=0.012) and ATM that was significant in males (P=0.0006). When gender-specific SF2-mean (0.31 and 0.35 for females and males; respectively) was considered, further discordance was observed where XRCC1 turned out not to be associated with radiosensitivity in males (P>0.05).

CONCLUSIONS

Although the variation in individual radiosensitivity was associated with certain SNPs, gender bias for both endpoints was evident. Therefore, assessing the risk of radiation exposure in females and males should be considered separately in order to achieve the ultimate goal of personalized radiation medicine.