cancer

Two meta-analyses conducted by the Cochrane Collaboration confirm that vaccination against human papillomavirus (HPV) prevents cervical cancer. Both articles bring together the results of 60 clinical trials and 225 studies involving more than 130 million people worldwide. According to Cochrane's press release, the result “is strong and consistent evidence” that vaccines against this virus are effective in preventing cervical cancer and precancerous changes, especially when given to young people before they are exposed to the virus. The reviews also confirm that HPV vaccines usually cause only mild and temporary side effects, such as pain in the arm. 

The use of hormonal contraceptives is associated with a small increase in the risk of breast cancer—one additional case of cancer for every 7,752 women who use these drugs—according to a Swedish study. The risk varies depending on the type of hormones administered, and is slightly higher with the use of contraceptives containing desogestrel. The study, published in JAMA Oncology, analyses data from a national registry between 2006 and 2019, with more than two million women aged between 13 and 49.

Between 2003 and 2017, the incidence of six types of cancer—thyroid, breast, colorectal, kidney, endometrial, and leukaemia—increased in young adults in three-quarters of 42 countries included in a study published in Annals of Internal Medicine. For all of these types of cancer, except colorectal, diagnoses also increased in adults over the age of 50. The study analyses data on 13 types of cancer and notes that those with increasing incidence include some of the most obesity-related cancers, such as endometrial and kidney cancer.

Although most cancer cases are considered sporadic, some are defined as hereditary, as certain individuals carry variants in their DNA that increase their risk. A team in the United States has analysed the genetic information of more than 400,000 people and concluded that the proportion of those with known risk variants is slightly higher than 5%. This figure is higher than expected: nearly double for variants of the BRCA1 or BRCA2 genes and between 10 and 20 times higher for variants related to thyroid cancer. The results are published in the journal JAMA in research letter format.

An international team has analysed cancer incidence and mortality worldwide using data available since 1990. Between then and 2023, there was an increase of almost 75% in deaths from this cause, with more than 40% of all deaths associated with preventable risk factors. Estimates indicate that by 2050 there will be a similar increase in mortality, due in part to the ageing of the population. The increase will be particularly pronounced in low- and middle-income countries. The results are published in The Lancet.

A study co-led by the Hospital Clínic-IDIBAPS in Barcelona presents a new methodology for studying the origin and evolution of cancer and predicting prognosis. This approach is based on the study of epigenetic DNA methylation signatures in the specific case of a type of leukemia, chronic lymphocytic leukemia. The researchers, who publish their results in the journal Nature, suggest that the tool could also be applied generally to other tumors.

For women diagnosed with early-stage breast cancer, the long-term risk of developing a second primary cancer is low, around 2–3 per cent higher than that of women in the general population. This is one of the conclusions of a study published by The BMJ, which analysed data from nearly half a million women diagnosed in England between 1993 and 2016 with early-stage invasive breast cancer who underwent surgery. During a follow-up period of up to 20 years, around 65,000 women developed a second primary cancer, but the absolute excess risk compared to the risks in the general population was small.

Over the past 20 years, a class of cancer drugs known as CD40 agonist antibodies has shown great potential, but also limited impact in patients and adverse reactions. In 2018, it was demonstrated that they could be improved to boost their effectiveness and limit serious side effects. A study published in Cancer Cell reports the results of using one of these drugs in a small phase 1 clinical trial: out of 12 patients, all with different types of metastatic cancer, six saw their tumors shrink, including two in whom they disappeared completely.

The introduction of artificial intelligence (AI) to assist in performing colonoscopies is associated with a reduction in the ability of healthcare professionals to detect precancerous growths (adenomas) in the colon without the aid of AI, according to an article published in The Lancet Gastroenterology & Hepatology.

In the US, the incidence of colorectal cancer increased in people aged 45-49 years in the period 2019-2022, after advancing the screening age from 50 to 45 years, according to a study published in JAMA. The use of mailed faecal tests made it possible to reach people in this age group, without affecting screening rates in people over 50, says another paper published in the same journal.