A new population-based study has revealed a strong link between colorectal cancer (CRC) in women and a wide range of adverse sexual and reproductive health conditions, with the risks most pronounced among women diagnosed before the age of 40. The research, published in the Journal of the National Cancer Institute on June 1, underscores the need for greater awareness and comprehensive post-cancer care for female CRC survivors—a topic that has often been overlooked in Thailand and worldwide.
While colorectal cancer rates and related mortalities have generally declined among older adults in high-income countries, including Thailand’s urban settings, attention is increasingly turning to the quality of life and ongoing health issues faced by survivors, especially younger women. Understanding the full spectrum of challenges is crucial for designing care protocols and counselling strategies that empower patients throughout survivorship.
The study, led by a pharmacoepidemiologist at the University of British Columbia who herself received an early-onset CRC diagnosis at 36, analyzed data from over 25,000 female patients diagnosed with CRC in British Columbia between 1985 and 2017. Each patient’s outcomes were matched to ten cancer-free controls of similar age and sex, resulting in a cohort exceeding 250,000 participants. Researchers specifically tracked the incidence of five outcomes: dyspareunia (pain during intercourse), abnormal bleeding outside pregnancy, pelvic inflammatory disease (PID), endometriosis, and premature ovarian failure (early menopause under age 40 requiring hormone therapy).
The findings were stark: female CRC survivors experienced a 67% higher risk for pain during sexual intercourse than women without cancer, and this risk soared to 90% in those diagnosed under 40. Surgery, chemotherapy, and radiation all independently heightened the risk of dyspareunia, with hazard ratios of 1.23, 1.25, and 1.24, respectively.
Chemotherapy was also found to significantly increase the risk of abnormal bleeding, and CRC survivors showed a 3.4-fold higher risk for PID compared to controls. Notably, those with left colon or rectal cancer faced even steeper risks for PID, amplified by 80% and 121% respectively. Radiation treatment was linked to a 56% increased rate of PID.
Endometriosis rates were nearly doubled in CRC survivors, with those undergoing surgical interventions facing an 80% greater risk. Perhaps most concerning for younger women, those given chemotherapy had a 164% higher probability of premature ovarian failure, an issue that can lead to early menopause and infertility concerns.
Significantly, the study found that many of these conditions did not appear immediately after diagnosis but often emerged three to four years later—during what is known as the “survivorship” stage. This delay underscores the importance of ongoing monitoring and robust, open discussions about quality of life and sexuality in cancer aftercare.
A Canadian assistant professor of obstetrics and gynecology, not involved in the study but interviewed by Medscape, stressed that every case is unique and that pain disorders or sexual health issues are often underdiagnosed and underreported. “When you have a woman with sexual pain, you really have to look into what the cause of it might be, regardless of age,” she said, pointing out that both the disease and its treatments—chemo, surgery, and radiation—can have profound multipronged impacts. For example, post-operative pain near the rectum can lead to pelvic floor muscle spasms and subsequently to intercourse pain, while radiation may cause vaginal stenosis.
For CRC patients, especially in Thailand where sexual health topics are sometimes considered sensitive, these findings signal the need for culturally sensitive information campaigns and enhancements in healthcare provider trainings. The implications are significant for ongoing reforms to the Thai universal healthcare system, which already provides comprehensive cancer care but may lack systematic protocols for sexual and reproductive health follow-up in cancer survivors. An expert at a leading cancer hospital in Bangkok, when asked for comment, noted that while Thai women are increasingly proactive about their health, stigma and modesty can still deter open dialogues about post-cancer sexual wellbeing. “We have to create safe spaces in our clinics and educate providers to ask the right questions in sensitive ways,” she said.
Thailand’s demographic and health transition also contributes urgency to this issue. As colorectal cancer rates creep upwards among younger Thais, with recent Ministry of Public Health data showing rising incidence in those under 50, the growing cohort of survivors may demand more tailored support services in coming years. This challenge echoes other countries’ experiences, but is compounded by local cultural attitudes surrounding sexual health, which may prevent timely reporting and intervention.
Importantly, the study’s authors caution that while associations between cancer, its treatments, and sexual health risks are clear, the precise biological mechanisms remain uncertain. More research is needed to understand the interplay between cancer type, site, treatment, and the range of outcomes observed. However, the study’s scale and rigorous analysis make clear that the risks are real and call for system-level change.
Beyond the statistics, the personal accounts shared in the study highlight real-world impacts. Many women only realize the effects on their sexual and reproductive health years into cancer survival—a critical period when emotional and psychological adjustment is as essential as physical recovery. For younger women, especially those who have not yet started families, the risk of premature menopause and fertility loss adds another layer of complexity and requires robust pre-treatment counselling.
Thai providers and policymakers can draw key lessons from the findings. Firstly, survivorship care programmes must move beyond focusing solely on disease recurrence and basic physical wellness—sexual and reproductive health deserve dedicated attention. Integrating screening for pain during intercourse, abnormal bleeding, and signs of ovarian dysfunction should become routine elements of aftercare. Moreover, providers should be trained to address sexual health openly, with compassion and cultural sensitivity.
Community awareness campaigns—building on Thailand’s strong history of public health innovation—could help destigmatize discussions about sexual side effects of cancer and empower women to seek help. Partner support groups, patient education workshops, and counselling services should also be scaled up, especially in regional hospitals where resources and experience may be limited.
Finally, as Thailand’s population ages and chronic disease becomes a greater focus, the mental health aspects of survivorship must not be forgotten. Addressing sexual and reproductive health holistically—including through referrals to specialists—is likely to strengthen trust in the system and improve long-term outcomes for Thai women and their families.
The path forward is clear: as cancer care in Thailand advances, so too must the frameworks for supporting survivors in every dimension of their lives. Thai health professionals, hospitals, and policymakers must work together to ensure women living after colorectal cancer do not suffer in silence, but instead receive the care, respect, and support they deserve.
For Thai patients and families, the takeaway is to have open discussions with oncology and gynaecology teams before, during, and after treatment. Seeking advice from multidisciplinary teams, including cancer specialists, fertility experts, and mental health professionals, is essential to optimizing quality of life post-cancer. Community organizations and patient advocates can also play a vital role in bridging gaps in information and emotional support.
Read the full report on Medscape for more scientific details and international expert perspectives: Medscape article.