Age and sex differences in bone metastasis of hepatocellular carcinoma in Japanese autopsy cases

Sex dimorphism in the tumor microenvironment - From bench to bedside and back

Cancer represents a significant cause of death and suffering in both the developed and developing countries. Key underlying issues in the mortality of cancer are delayed diagnosis and resistance to treatments. However, improvements in biomarkers represent one important step that can be taken for alleviating the suffering caused by malignancy. Precision-based medicine is promising for revolutionizing diagnostic and treatment strategies for cancer patients worldwide. Contemporary methods, including various omics and systems biology approaches, as well as advanced digital imaging and artificial intelligence, allow more accurate assessment of tumor characteristics at the patient level. As a result, treatment strategies can be specifically tailored and adapted for individual and/or groups of patients that carry certain tumor characteristics. This includes immunotherapy, which is based on characterization of the immunosuppressive tumor microenvironment (TME) and, more specifically, the presence and activity of immune cell subsets. Unfortunately, while it is increasingly clear that gender strongly affects immune regulation and response, there is a knowledge gap concerning differences in sex-specific immune responses and how these contribute to the immunosuppressive TME and the response to immunotherapy. In fact, sex dimorphism is poorly understood in cancer progression and is typically ignored in current clinical practice. In this review, we aim to survey the available literature and highlight the existing knowledge gap in order to encourage further studies that would contribute to understanding both gender-biased immunosuppression in the TME and the driver of tumor progression towards invasive and metastatic disease. The review highlights the need to include sex optimized/genderized medicine as a new concept in future medicine cancer diagnostics and treatments.

Female sex is associated with a lower risk of bone metastases and favourable prognosis in non-sex-specific cancers

Background

The objectives were to investigate the disparity in the prevalence of bone metastases (BM) between the sexes and to assess the effect of female sex on the development and prognosis of BM.

Methods

Cases of invasive non-sex-specific cancers diagnosed between 2010 and 2015 in the Surveillance, Epidemiology, and End Results (SEER) program were used. The prevalence of BM was calculated by combining the prevalence of BM among different cancers. Multivariable logistic regression and proportion hazard regression were conducted to investigate the effect of female sex, and the results were pooled by meta-analysis.

Results

The pooled prevalence of BM among male and female patients was 2.3% (95% CI: 1.6–3.2%) and 1.8% (95% CI: 1.2–2.6%), respectively. The pooled prevalence of BM dramatically decreased for patients aged 11–40 years old, plateaued for patients aged 41–90 years old and increased for patients aged > 90 years old in both male and female patients. Meta-analysis suggested that female sex had a protective effect on the development of BM (pooled OR = 0.80; 95% CI: 0.75–0.84; p < .001) and a favourable prognosis for respiratory system cancers (pooled HR = 0.81; 95% CI: 0.71–0.92; p < .001). However, no significant associations existed for other cancers. Male non-sex-specific cancer patients and those with male-leaning genetic variations or hormonal status have a greater likelihood of developing BM than female patients.

Conclusions

Female sex was associated with fewer BM in various non-sex-specific cancers, and the effect was constant with changes in age. Female sex showed a protective effect exclusively on the prognosis of respiratory system cancers.

Effect of sex in the MRMT-1 model of cancer-induced bone pain

An overwhelming amount of evidence demonstrates sex-induced variation in pain processing, and has thus increased the focus on sex as an essential parameter for optimization of in vivo models in pain research. Mammary cancer cells are often used to model metastatic bone pain in vivo, and are commonly used in both males and females. Here we demonstrate that compared to male rats, female rats have an increased capacity for recovery following inoculation of MRMT-1 mammary cells, thus potentially causing a sex-dependent bias in interpretation of the data.

Gender difference in bone metastasis of human small cell lung cancer, SBC-5 cells in natural killer-cell depleted severe combined immunodeficient mice

Lung cancer frequently develops multiple organ metastases, which thus makes this disease a leading cause of malignancy-related death worldwide. A gender difference is reported to affect the incidence and mortality of lung cancer; however, whether and how the gender difference is involved in lung cancer metastasis is unclear. This study evaluated the gender difference in multiple organ metastases in human small cell lung cancer (SBC-5) cells by using natural killer cell-depleted severe combined immunodeficient mice. Among multiple organ metastases, only bone metastasis formation significantly increased in female mice in comparison to males, while no significant difference was observed in the metastases to the liver and lungs. The suppression of androgen by castration or androgen receptor antagonist treatment in male mice also induced a significant increase of bone metastases. The number of osteoclasts in the bone metastatic lesions was greater in female mice and in mice with androgen suppression than in control male. However, there was no significant difference in the serum concentration of parathyroid hormone-related protein (PTHrP) associated with gender or androgen suppression. An in vitro study also indicated that sex steroid treatment had no effect on the proliferation or PTHrP production in SBC-5 cells. These results indicate that the balance of sex steroids therefore plays an important role in the formation of bone metastasis in small cell lung cancer, and suggests diverse mechanisms of interaction between cancer cells and host cells in the bone microenvironment.

Bone metastases of hepatocellular carcinoma after liver resection

Between January 1985 and July 1990, 323 cases of hepatocellular carcinoma underwent liver resection in our department. Bone metastases were found in 12 of these cases (3.7%). Bone metastases were mainly found in vertebral bone (58.3%) and pelvic bone (41.7%). The time interval to the development of bone metastasis after liver resection was closely related to the presence of intrahepatic metastasis and the stage at operation. In all cases, the initial clinical symptom was pain and/or motor disturbance. Radiotherapy was performed in 10 cases and transcatheter arterial embolization or surgery was performed in 4 cases. The pain or neurological symptoms improved with these therapies in all cases. Cumulative survival was 1 year in 74%, 2 years in 34%, and 3 years in 17%, respectively.