Cancer & HIV: Scott Dryden-Peterson Explores the Connection

Scott Dryden-Peterson and Hermann Bussmann
Scott Dryden-Peterson and Hermann Bussmann

Since the introduction of antiretroviral treatment in the 1990s, a diagnosis of AIDS no longer means imminent death. Many people with HIV now live long, relatively healthy lives. Mortality rates, however, are still higher in people with HIV and they die younger. Researchers would like to know why.

“We know that HIV patients are at increased risk of developing cancer, heart attacks, and strokes,” said Dr. Scott Dryden-Peterson, a doctor at the Harvard AIDS Initiative (HAI). “If they survive for longer, they have more time to develop these illnesses.” Scott’s research explores the interaction of HIV and cancer in resource-limited settings, particularly sub-Saharan Africa, where over 20 million people are living with HIV.

Cancer in Africa

The AIDS epidemic has caused a major change in cancer patterns. Cervical cancer, an AIDS-related cancer, is now the most common cancer in African women. Kaposi sarcoma, an AIDS-defining cancer that can cause purple or red lesions on the skin, is the most common cancer in men and the third most common in women.

AIDS is not the only reason for escalating cancer rates in Africa. Other factors include an aging population, an increase in smoking, and unhealthy changes in diet.

Historically, cancer has been a low public health priority in Africa. Governments have been more concerned with the threat of infectious diseases, such as AIDS, malaria, and tuberculosis. A lack of medical records makes it difficult to study changing cancer rates. Data on cancer is just beginning to be collected in Africa and there is little or no historical data to compare it with.

Botswana, where Scott Dryden-Peterson conducts research, is the only African country that has a single national cancer registry. Scott is looking at rates and types of cancer in those living with HIV. He is also looking at the difference in rates between people who have HIV and people who don’t.

“For an individual woman with breast cancer and HIV, there isn’t a big epidemiologic signal that the risk for breast cancer is elevated, although in Botswana, clinicians think there is an increased risk because they see a lot of very young women with HIV who also have advanced breast cancer,” said Scott. His research will help confirm whether the data backs up doctors’ anecdotal evidence.

From Environmental Science to Infectious Disease

Working as an AIDS doctor in Africa wasn’t an obvious choice for Scott. He grew up in the temperate rainforest of southeast Alaska. His parents were both schoolteachers and are now commercial salmon fishermen. Scott and his sister spent part of each summer on the family’s fishing boat.

As an undergrad at Harvard, Scott studied environmental science and was a star swimmer. He worked in a forest research station in Borneo before attending Harvard Medical School. A fellowship in infectious diseases took him to the Botswana Harvard AIDS Institute Partnership (BHP) for the first time in 2008. Scott lived in Botswana with his wife and daughter for a year and a half.

These days, Scott has two daughters and spends three months of the year in Botswana. When in Boston, Scott is an instructor at Harvard Medical School and an attending physician at the oncology infectious disease service at Brigham & Women’s Hospital. He sees cancer patients, but he treats their infections rather than their cancer. “It’s a specialty within a specialty,” he says.

Interplay

Scott likes the blend of patient care, teaching, and investigation. He is the Principal Investigator of a pilot study, HIV and Malignancy in Botswana. For the study, he and his colleagues have established the Botswana Prospective Cancer Cohort. Started in 2010, the cohort enrolls all cancer patients at Princess Marina, the largest hospital in Botswana. About two-thirds of the country’s cancer cases are treated there. Patients who don’t know their HIV status are tested for the virus.

Scott’s study will follow patients into the future and record their health outcomes. Though the study is still in progress, there have already been major findings. Of the patients with cancer in Botswana, two-thirds of them have HIV. “It was surprising,” said Scott. “I didn’t think it would be nearly that high.”

Also surprising, many of the people presenting with Kaposi sarcoma had been on HIV therapy for an average of five years before they developed their cancer, suggesting that their cancers were still developing despite being on antiretrovirals (ARVs). “That was somewhat discouraging and surprising at the same time,” said Scott. “We’re evaluating the impact of ARVs and other risk-modifying factors on the incidence of cancer and patient outcomes.”

Information for Solutions

The results from Scott’s study will provide much-needed information about the prevalence of cancers in Africa, both in people with and without HIV. Working with the Botswana Ministry of Health, Scott is helping to establish guidelines for treating cancers in a country that until recently sent most of its cancer patients to South Africa for treatment.

Scott Dryden-Peterson and President George W. Bush in Botswana July 2012
Scott Dryden-Peterson and President George W. Bush in Botswana July 2012

“In many places in sub-Saharan Africa, the quality of medical care went up dramatically as AIDS therapy came in,” explained Dr. Max Essex, Chair of HAI. “People recognized the opportunities to both diagnose and treat more complicated diseases.”

As AIDS tragically changed Africa for the worse, the response to AIDS brought about constructive changes to the knowledge, infrastructure, and the expectations of what is possible. “Having learned that drug prices for treatment of AIDS could go down dramatically, many people ask why can’t drug prices go down as dramatically for treating forms of cancer,” said Essex. “And in many cases they can.”

Scott Dryden-Peterson, like many of his young colleagues, is expanding the definition of what it means to be an AIDS researcher. His work exploring how HIV interacts with cancer and other diseases will become increasingly important as the epidemic matures and more and more patients grow old. Scott recently received a prestigious K23 Career Development Award from the National Institutes of Health. While continuing his work, he’ll begin a Master’s in Epidemiology at the Harvard School of Public Health to further enhance his research skills.