A major study of three of the most common cancers in women, conducted by the Cancer Survival Group at the London School of Hygiene & Tropical Medicine, found variations in the stage of disease at diagnosis, the type of treatment, and the extent to which treatment was consistent with international guidelines.
Published by Allemani et al in The Lancet, the findings from the VENUSCANCER project, which is embedded within the CONCORD program for the global surveillance of cancer survival, provide the first global picture of pathways to care, which is crucial evidence to support initiatives aimed at improving cancer control worldwide.
Key Findings
One in five women with breast or cervical cancer in low- and middle-income countries are diagnosed at an early stage, compared with more than one in three in high-income countries, new research suggests. For ovarian cancer, the proportion of women diagnosed with early-stage disease was generally lower than 20% (one in five) worldwide, although the situation remains slightly worse for women in low- and middle-income countries.
Data from more than 275,000 women in 39 countries revealed that surgery was generally offered to women with early-stage cancer in most countries, although not necessarily consistently with international guidelines. But the researchers say too many women, especially in low- and middle-income countries, are not being diagnosed until the disease has become too advanced.
The proportion of women whose cancer was detected at an early stage was 40% or higher in high-income countries for cervical or breast, but much lower in low- and middle-income countries, at below 20% for all three cancers, apart from Cuba (30% for breast) and Russia (36% for cervical and 27% for ovarian). These differences mean that women’s chances of survival in most low- and middle-income countries will be lower than in high-income countries.
Metastatic breast cancers accounted for less than 10% of diagnoses in most high-income countries, but were more frequent in low- and middle-income countries (range = 2%–44%). Advanced cervical cancers were lower than 15% of cases in most countries worldwide.
When it came to treatment for the three cancers, surgery was offered to 78% of women in high-income countries and 56% of women in low- and middle-income countries, but initial treatment for early-stage tumors was more often consistent with clinical guidelines for cervical and ovarian cancer than for breast cancer.
Nonsurgical treatment, such as chemotherapy or hormonal therapy, was more often consistent with international clinical guidelines than surgery.
Consistent with clinical guidelines, women with early-stage breast cancer were treated with breast-conserving surgery plus radiotherapy (range = 67%–78%) in most European countries. The proportion was lower in Canada (60%) and the United States (53%). By contrast, in low- and middle-income countries, 30% to 70% of women with early-stage breast were treated with mastectomy. However, mastectomy was also common in the United States, Canada, Estonia, the Netherlands, and Portugal.
The authors highlighted the importance of a patient’s choice in deciding on the type of treatment or surgery they receive, but also pointed out that these decisions are often based on socioeconomic factors, education, lack of treatment facilities, distance from the treatment facility, or fear of recurrence.
Breast-conserving surgery without radiotherapy is mainly offered to women older than 70 years with estrogen receptor–positive breast cancer. But the researchers said the lack of radiotherapy facilities and surgeons trained in breast-conserving surgery is the main reason that a high proportion of women in low- and middle-income countries have mastectomies. Other reasons can come into play as part of this complex global picture. For example, in Thailand, older women tend to prefer mastectomy, due to the belief that it offers a better chance of curing their cancer, while some health insurance policies in the United States do not cover radiotherapy.
Expert Commentary
Lead author and principal investigator of VENUSCANCER Claudia Allemani, PhD, Professor of Global Public Health at the London School of Hygiene & Tropical Medicine, said: “This study was a major undertaking, creating the largest and most detailed global population-based database for three of the most common cancers in women to date, including data on stage, staging procedures, treatment, and biomarkers. VENUSCANCER offers the first real-world picture of patterns of care and consistency of treatment with clinical guidelines, on a global scale.”
“Treatment that is consistent with established international clinical guidelines for standard care still varies worldwide; however, it’s encouraging to see that if women are diagnosed early, prompt access to optimal treatment for breast, cervical, and ovarian cancers has become more accessible for early-stage tumors in most countries. But this only helps if cancer is detected early enough. Sadly, the proportion of women with cancer who are diagnosed at an early stage is still far too low, especially in low- and middle-income countries.”
“Evidence from this study should help to inform global policy on cancer control, such as WHO’s Global Breast Cancer Initiative and the Cervical Cancer Elimination Initiative.”
“Efforts to promote improvement of early cancer detection should continue, in all countries. More radiotherapy facilities and specially trained cancer surgeons are also needed to ensure that women in low- and middle-income countries have access to a full range of treatment options. In some high-income countries, health insurance policies should include radiotherapy for economically disadvantaged women.”
“Population-based cancer registries are key to assessing and monitoring the consistency of treatment with clinical guidelines and their impact on the survival of patients with cancer. To guarantee the timeliness and completeness of data on stage and treatment, governments should include the provision of stable financial support for population-based cancer registries in any cancer control plan,” concluded Dr. Allemani.
Senior study author Veronica Di Carlo, PhD, Research Fellow in the Cancer Survival Group at London School of Hygiene & Tropical Medicine, said: “We found there was variation in the extent to which countries followed international clinical guidelines. This suggests that more needs to be done to tailor internationally agreed[-upon] recommendations to local needs and resources, to simplify them, and to make them available in local languages. Women everywhere need to be able to discuss their treatment with medical professionals and make decisions in the knowledge that they can access the best available options according to recommended guidelines.”
The authors acknowledged limitations of the study, such as gaps in the data provided by some countries.
Disclosure: The study was funded by a European Research Council Consolidator Grant. For full disclosures of the study authors, visit thelancet.com.
