A case-control study of the joint effect of reproductive factors and radiation treatment for first breast cancer and risk of contralateral breast cancer in the WECARE study

Effect of Stereotactic Body Radiation Therapy Combined with Thermoplastic Fixation on Set-Up Errors in Breast Cancer Patients Undergoing Radiotherapy

Objective

To investigate the effect of stereotactic radiotherapy (SBRT) combined with thermoplastic fixation on set-up error in breast cancer (BC) patients undergoing radiotherapy.

Methods

Ninety BC patients undergoing radiotherapy who were treated in our hospital (May 2019-May 2020) were selected as the research objects and equally divided into the experimental group and control group according to the order of hospitalization, with 45 patients in each group. The control group received conventional radiotherapy combined with breast bracket, and the experimental group received SBRT combined with thermoplastic fixation. The incidences of adverse reactions, 1-year survival rates, and set-up errors were compared between the two groups.

Results

Compared with the control group, the experimental group had much lower total incidence of adverse reactions and remarkably higher 1-year survival rate. The translational errors (X direction, Y direction, and Z direction), translational errors after rotation (X direction, Y direction, and Z direction), and rotation errors (X direction, Y direction, and Z direction) in the experimental group were obviously lower compared with those in the control group.

Conclusion

Implementing SBRT combined with thermoplastic fixation in BC patients undergoing radiotherapy can effectively improve set-up efficiency and treatment accuracy and reduce set-up errors. Compared with the breast bracket, the combination of SBRT and thermoplastic fixation has higher application value, and further studies are conducive to providing patients with a better solution plan.

Pregnancy-associated cancer and the risk of second primary cancer

PURPOSE

Hormonal changes related to pregnancy and lactation among women treated for cancer might influence the risk of second primary cancer. We investigated whether pregnancy near the time of breast cancer, Hodgkin lymphoma or other cancer diagnoses is associated with increased risk of developing a new primary cancer.

METHODS

Women born after 1 April 1935 diagnosed with cancer at ages 15-44 years during 1968-2006 were identified in the Danish Cancer Registry. Information about pregnancies from various nationwide registers was used to identify women with a pregnancy-associated cancer defined as a cancer diagnosed 6 or fewer months before the pregnancy, during the pregnancy or up to 1 year after the pregnancy. Second primary cancers were ascertained through 2013, and hazard ratios (HRs) were calculated using Cox regression models adjusted for age, calendar-period and number of pregnancies with the reference defined as cancer not associated with a pregnancy.

RESULTS

We identified 2,974 women with pregnancy-associated cancer and 31,970 women who were not pregnant near the time of their cancer diagnosis. There was no association between pregnancy-associated cancer and a second cancer (HR 0.91; 95% CI 0.79-1.05). Among 680 women with either breast cancer or Hodgkin lymphoma associated with pregnancy, a HR of 1.16 (95% CI 0.87-1.56) for second breast cancer was observed based on 48 cases.

CONCLUSION

While hormonal changes might stimulate development of specific cancers, in particular breast cancer, it is reassuring that risk of breast and other second cancers was not related to pregnancy near the time of a first primary cancer diagnosis.

Circular RNA circ_0084927 regulates proliferation, apoptosis, and invasion of breast cancer cells via miR-142-3p/ERC1 pathway

OBJECTIVE

We aimed to investigate the mechanism of circular RNA circ_0084927 in the progression of breast cancer (BC).

METHODS

The levels of circ_0084927, miR-142-3p, and ELKS/RAB6-interacting/CAST family member-1 (ERC1) mRNA in the BC tissues and cells were detected by qRT-PCR. CCK8, colony formation, Transwell, and flow cytometry assays were performed to examine the cell proliferation, colony formation, cell invasion, and apoptosis, respectively, in the BC cells with regulated expressions of circ_0084927, miR-142-3p, and ERC1. RNase R treatment was employed to verify the circular structure of circ_0084927. Nucleocytoplasmic separation experiment, bioinformatics analysis, dual-luciferase reporter assay, and RNA immunoprecipitation were performed to investigate the ceRNA mechanism of circ_0084927.

RESULTS

High levels of circ_0084927 and ERC1 and low levels of miR-142-3p were detected in the BC tissues and cells. Knockdown of circ_0084927 promoted apoptosis and inhibited proliferation, colony formation, and invasion of BC cells (all P<0.05), whereas overexpression of circ_0084927 in the BC cells achieved the opposite effects. miR-142-3p is the target of circ_0084927. Overexpression of miR-142-3p could inhibit BC cell proliferation, colony formation, and cell invasion and induce apoptosis of the BC cells (all P<0.05), and the effects of miR-142-3p knockout on the BC cells could be reversed by silencing circ_0084927. miR-142-3p could target ERC1. Both ERC1 silencing and circ_0084927 knockout in the BC cells could achieve the tumor-suppressing effect, and this effect could be more remarkable under simultaneous ERC1 silencing and circ_0084927 knockout (all P<0.05).

CONCLUSION

Circ_0084927 can promote the progression of BC by regulating the miR-142-3p/ERC1 axis.