BOSTON -- There have been many strides in the prevention, screening and treatment of breast cancer and many more on the way.

Locally, the future of breast cancer screening is already under way at Massachusetts General Hospital.

Dr. Elizabeth Rafferty explained, "Breast Tomosynthesis is essentially a three-dimensional mammogram. Mammography is the only test that's been shown to decrease the mortality rate from breast cancer so it's the foundation of everything that we do in breast imaging. But we know it's not perfect."

At MGH researchers use a machine some hope will replace mammograms as the standard for diagnostic care. Women say Digital Tomosynthesis is more comfortable than a mammogram. Radiologists say images are easier to read.

"It allows you to look at one area of the breast at a time and allows you to look at that without the overlap of all the surrounding tissues," said Dr. Rafferty.

FDA approval is pending.

"During the next five years we and other people are going to have a lot of new data that I think will lead us toward better ways to prevent breast cancer," said Dr. Walter Willette of the Harvard School of Public Health.

Right now the best prevention advice includes limiting alcohol, maintaining a healthy weight, exercising and eating a low fat diet. It's the nutrition angle that fascinates Dr. Willette.

"The first thing that has shown up and is well established now is that alcohol consumption is related to increased risk of breast cancer. It's surprising that quite small amounts, say like one drink every other day does measurably cause a small increase in breast cancer," said Willette. "And if we have two drinks a day it increases our risk by about 25 or 30 percent compared to a woman who doesn't drink."

So drop that drink and get vitamin D in your system instead.

"For breast cancer specifically, in the nurses health study, we've seen about a 25 percent lower risk of breast cancer among women with the highest blood levels of vitamin D," Willette said.

The natural source of vitamin D is sunlight, but most of us take steps to reduce our exposure. Vitamin D can be found in fish, milk and yogurt, but you'll want to take a supplement to get to at least 1,000 units a day.

There's a lot of research going into finding the best treatment for breast cancer. At Beth Israel Deaconness Medical Center, Dr. Lewis Cantley studies signal transduction. Simply put, it's a way that cells communicate with one another.

This work is important because it's becoming clearer that a variety of diseases, including breast cancer, are linked to defects in the signal transduction process. The goal is to target the problem with more precision.

"We're seeing more and more examples of targeted therapies having more significant benefits and fewer side effects than chemotherapy," said Cantley. "So instead of throwing a sledgehammer at cancer and hope that in the process of killing the cancer you don't kill the patient, the idea is find out what's actually driving that particular person's cancer. And then find a drug that targets that particular event. That's what we do."

Cantley said right now targeted therapies help manage cancer as a chronic disease, but he thinks science can do better.

"Our goal is to convert the drugs that manage the disease into ones that can knock it out," he said.