SUNDAY, Sept. 23 (HealthDay News) -- A comprehensive look at the genetic blueprint of breast cancer has revealed new insights into the disease -- including the discovery that certain breast and ovarian tumors may be closely related.

Basal-like breast tumors -- one of the most deadly subtypes of breast cancer -- are genetically more similar to ovarian cancer than to other breast cancers, the new research found.

In this study, the scientists used six different technologies to analyze 348 tumors from women with breast cancer. They looked for defects in DNA, RNA and proteins in the tumors.

They confirmed the existence of four main subtypes of breast cancer -- luminol A, luminal B, HER2 and basal-like -- and found unique genetic and molecular signatures within each of the subtypes.

The findings add to growing evidence suggesting that tumors should be catalogued and treated based on the genes that are disrupted rather than their location in the body, the researchers said.

"With this study, we're one giant step closer to understanding the genetic origins of the four major subtypes of breast cancer," study co-leader Dr. Matthew Ellis, chair of medical oncology at Washington University School of Medicine in St. Louis, said in a university news release.

One oncologist said the findings on breast cancer's diversity echo her own experience in treating patients.

"The diversity of breast cancer is instinctual to a practicing breast surgeon who has seen women with breast cancer, presumably the same stage, have differing outcomes with respect to recurrence and survival," said Dr. Donna-Marie Manasseh, director of breast surgery at the Maimonides Breast Cancer Center in New York City. "This research validates what we have suspected."

According to Ellis, the new study suggests that most basal-like breast tumors and ovarian tumors have similar genetic origins and potentially could be treated with the same drugs.

Basal-like tumors account for about 10 percent of all breast cancers and disproportionately affect younger and black women in the United States. Basal-like tumors include most triple-negative breast tumors, which are often aggressive and do not respond to therapies that target hormone receptors or to standard chemotherapies.

"Now, we can investigate which drugs work best for patients based on the genetic profiles of their tumors. For basal-like breast tumors, it's clear they are genetically more similar to ovarian tumors than to other breast cancers. Whether they can be treated the same way is an intriguing possibility that needs to be explored," Ellis explained.

Another expert agreed that this type of insight moves medicine closer to a "personalized" approach to therapy.

"This research is geared toward finding ways to individualize cancer treatment," said Dr. Stephanie Bernik, chief of surgical oncology at Lenox Hill Hospital in New York City. "When treating breast cancer, we offer specific therapies that have been tested on large populations of cancer patients. However, one treatment is not necessarily good for all."

According to Bernik, "this research helps move us to the point where we will look at a tumor's genetic makeup and tailor a specific treatment that will attack the tumor cells based on the tumor's genetic fingerprint."

Manasseh said the new study "provides hope to many woman and clinicians who battle breast cancer every day."

"Breast cancer is not just one disease and, therefore, requires not just one type of therapy but rather different disease types that require specific therapies targeted for each type," she added. "Targeted therapies allow for more effective treatment of tumors, while minimizing the treatment of tumors with less effective therapies and their subsequent side effects."

The study was published online Sept. 23 in the journal Nature.

More information

The American Cancer Society has more about breast cancer  .

WEDNESDAY, Sept. 19 (HealthDay News) -- Women who experience early menopause may face double the risk of heart disease and stroke, according to a new study.

This increased risk is true across different ethnic backgrounds and is independent of traditional heart disease and stroke risk factors, the researchers said.

The study included more than 2,500 women, aged 45 to 84, who were followed for between six and eight years. Twenty-eight percent of the women reported early menopause, which occurs before the age of 46.

Women with early menopause had twice the risk of heart disease and stroke compared to other women. The overall number of women in the study who suffered heart attacks (50) and strokes (37) was small, however, the researchers noted.

When a woman's periods have stopped for a year, she has reached menopause.

The study -- which found an association between early menopause and heart risk, but not a cause-and effect connection -- appears in the October issue of the journal Menopause.

"If physicians know a patient has entered menopause before her 46th birthday, they can be extra vigilant in making recommendations and providing treatments to help prevent heart attacks and stroke," study leader Dhananjay Vaidya, an assistant professor in the division of general internal medicine at the Johns Hopkins University School of Medicine in Baltimore, said in a university news release.

"Our results suggest it is also important to avoid early menopause if at all possible," Vaidya said.

For example, smokers reach menopause an average of two years earlier than nonsmokers, so quitting smoking may delay menopause. Other factors that influence the onset of menopause include heredity, diet and exercise.

The researchers also found that the increased risk of heart disease and stroke associated with early menopause was similar whether early menopause occurred naturally or because of surgical removal of reproductive organs. Vaidya noted that women who have a hysterectomy (uterus removal) often have their ovaries removed, which leads to rapid menopause.

"Perhaps ovary removal can be avoided in more instances" in order to delay menopause and possibly protect patients from heart disease and stroke, Vaidya suggested.

Cardiovascular disease is the leading cause of death for women in the United States, according to the U.S. Centers for Disease Control and Prevention.

More information

The U.S. Office on Women's Health has more about early menopause.

WEDNESDAY, Sept. 19 (HealthDay News) -- Expectant mothers are often told they shouldn't smoke, but a new study reports that even secondhand smoke has a negative effect on the brain development of newborns.

Pregnant women who smoke or inhale secondhand smoke put their children at risk for learning difficulties, attention-deficit/hyperactivity disorder and obesity, the researchers from Spain said. The investigators also found that babies who have been exposed to nicotine have impaired physiological, sensory, motor and attention responses in the first two to three days of life.

For the study, scientists from the Behaviour Evaluation and Measurement Research Center of the Rovira i Virgili University examined 282 healthy babies 48 to 72 hours after they were born to assess their behavior and responses.

Of the mothers involved in the study, 22 percent smoked during their pregnancy and nearly 6 percent were exposed to secondhand smoke. Among those who smoked, 12.4 percent had no more than five cigarettes per day, 6.7 percent had between six and 10 cigarettes daily and 2.8 percent smoked 10 to 15 cigarettes, the investigators found.

The study findings indicated that the babies born to women who smoked or were exposed to secondhand smoke were less able to block stimuli that could alter their central nervous system.

The research also revealed that babies of women who inhaled secondhand smoke had poor motor development. In addition, the newborns of mothers who smoked during pregnancy were less able to regulate their physiological, sensory, motor and attention responses.

"Newborns who have had intrauterine exposure to nicotine, whether in an active or passive way, show signs of being more affected in terms of their neurobehavioral development," stated the study's lead author, Josefa Canals Sans, in a Spanish Foundation for Science and Technology news release.

The study authors specifically advised that women should be warned about the effects of secondhand smoke on fetus and infant development.

The study was published recently in Early Human Development.

While the study found an association between maternal smoke exposure and infant brain development, it did not prove a cause-and-effect relationship.

More information

The U.S. Environmental Protection Agency has more about the health effects of secondhand smoke.