Medical school and breast cancer research pioneers Drs. Susan Love and Ellen Mahoney left the audience laughing, updated and hopeful in the aisles of Van Duzer Theatre last week — no mean feat when roughly half the audience admitted to battling breast cancer and most of the rest supported someone who had.

“They are not Osama bin Laden,” Love said of the breast cancer cells that have long been thought of as foreign invaders that blow lives to pieces. “They are Timothy McVeigh, our own terrorist.”

Determining what makes a homegrown member of the neighborhood blossom into a terrorist, be it in Oklahoma City or the breast, is only part of the challenge embraced by today’s cancer researchers.

Love and Mahoney want to move beyond treatment after the fact — which used to set in motion the one-size-fits-all response to breast cancer of chemotherapy, surgery and radiation — to identify, in Love’s words, “cells just thinking about being cancer when they grow up.”

“It’s not just the cells,” she added. “It’s the local neighborhood that’s as important as the cells themselves.”

That is proving true for many cancers, 70 percent of which Harvard Health Letter physician-editors Robert Weinberg and Anthony Komaroff say could be prevented “if we grew thinner, exercised regularly, avoided diets rich in red meat (substituting poultry, fish and vegetables) and ate diets rich in fruits and vegetables, and stopped using tobacco.”

“Lifestyle changes the environment,” Love said. “If you exercise on a regular basis, it reduces the risk of recurrence.

“If you’re overweight with breast cancer and menopausal, that increases the risk of recurrence.”

Love pointed to a study where nests of cells primed to become cancer were separately placed on healthy cells and cancerous cells. The primed cells took on the habits of each in a kind of cellular peer pressure that suggests that controlling or eliminating bad influences is worthy of more research and personal effort.

“You don’t care if you have a nest of quiet cancer cells — if you keep them quiet,” Love told the audience.

With five different kinds of breast cancer now on record, Love said the biggest change in the past decade has been moving to targeted treatments for specific cancers. Rather than the past approach of slash, burn and poison — “And you know the American way: more is always better” — treatments are matched to each cancer to extend the quality and length of life by quieting cancer cells.

As an example, Love cited the breast cancer drug Tamoxifen.

“You can stop taking Tamoxifen for five years and the benefit persists for 20 years,” she said. “It puts cells to sleep until they wake up. I don’t know how (they wake up). If I knew, we’d have the Nobel Prize.”

Mahoney isn’t sure the McVeigh analogy is accurate, if for no other reason than that McVeigh displayed some organizational smarts.

“They’re too stupid to make it on their own,” Mahoney said of the quiet cells, the vast majority of which will stay quiet and never become the cancer that is traced to one renegade cell.

“I don’t know if it’s survival of the fittest or the luckiest.”

What Love and Mahoney do know is much more about the breast than the “precious little” that was on record when they were among the 5 percent of medical students who were female in the early 1970s.

“If you looked at a picture of the anatomy of a breast, it was a breast and a nipple,” Mahoney said. “For years and years, they thought it was a hunk of stuff. There was no regard for the internal anatomy.”

Now, the pair knows all breast cancer starts in the milk ducts. Each breast has six to nine ducts, each of which branches through the breast like the veins in blue cheese. Each duct produces milk from the lobule and carries the milk to a separate outlet at the nipple.

“It’s not one organ,” Mahoney said of the ductal system. “They don’t interconnect. Cancer is a disease of one sick duct. What happens in that duct, stays in that duct.”

The American Cancer Society estimates 60,000 cases of ductal carcinoma in situ annually, but Mahoney said only 30 percent of women diagnosed with DCIS will ever develop invasive breast cancer.

For the last few years, Love and Mahoney have been conducting a Band-Aid study in China in the hope of creating a simple screening test to replace the mammograms. The best screening test available today is unavailable in much of the world and largely ineffective in picturing the denser breasts of young women, they said.

The pair created a dipstick of sorts that will react to five markers in breast fluid, which undergoes changes when some ductal cells become primed for cancer or are cancerous.

“Tape it down (over the nipple), then massage and squeeze,” Love said of the Band-Aid.

A Band-Aid that becomes blue means the cells are primed for cancer. If a line shows up, then cancer is present.

“It’s only halfway created,” Love said of the prototype that could make screening for breast cancer almost as easy as a home pregnancy test. Love had a prototype meeting Friday.

The next step depends on the outcome of a study being led by Mahoney and conducted in Humboldt County. They are looking for 30 women diagnosed by core biopsy with ductal carcinoma in situ — the earliest form of breast cancer.

“If milk comes out, we can go in the other direction,” Love said.

Mahoney will do exactly that by inserting into the impacted duct a low dose of Doxil, a drug known to kill breast cancer cells, a few weeks before the scheduled lumpectomy or mastectomy.

Surgery removing the impacted area is the standard of treatment now when the telltale calcifications of dead cancer cells show up on a mammogram and are followed with a core-biopsy confirmation.

Mahoney will monitor the aftermath before and after the surgery and will receive a pathology report.

Love called the study “safe and very intriguing.”

The California Breast Cancer Research Project rated it tops among the 50-plus research projects seeking funding in its 2007 selection process.

Mahoney and Love hope to bring breast cancer treatment to where cervical cancer has come in the last 40 years in the U.S.

“When you had an abnormal Pap smear, it led to a hysterectomy and your fertility was gone,” Love recalled of her grandmother’s treatment options. It was an approach similar to the mastectomy for DCIS: It worked, but at great cost.

Modified surgery was the next step.

“Now we’ve figured out it’s a sexually transmitted disease,” Love said. “My daughter can have a vaccine. There’s no reason we can’t do that in breast cancer.”

“Treatments have gotten easier to tolerate,” Mahoney said of the changes she’s seen, particularly chemotherapy that has decreased from two years to four to six months. “But we haven’t made real progress to get rid of the problem. In our lifetime, we will see that happen.”

Love envisions a day when an abnormal Band-Aid test leads to squirting the ducts to prevent the cells, primed or healthy, from turning cancerous. Another possibility: a Drano approach to remove the faulty lining of a duct.

“If you don’t have the cells, you can’t get it,” Mahoney said. “Get rid of the cells.”

“We know where it starts; we know where to find it,” Love said. “We’re going beyond the cure to prevention and eradication of the disease.”

Marla Gleave, whose mother endured breast cancer and whose brother tackled testicular cancer, came away hopeful for her daughter’s future and her own.

“They are so convinced it’s going to become a preventive,” she said. “I left feeling my daughter isn’t going to have to deal with it and came out thinking if I got the disease, I could conquer it. It was hopeful and inspiring.”