It was the summer before her senior year in college. And Colleen Cappon was looking forward to the same thing most 21-year-olds look forward to: relaxing, spending time with friends and, yes, even a little partying.

But this past July, she received a shock that would change the outcome of her summer and follow her as she completes her college career.

Breast Cancer?

“I just put my bra on one day and it just so happened that the lump that I had was really hard and really big and it was really close to the skin,” Cappon explained. "So it was really easy to feel and I was wondering what it was and went to my gynecologist.”

Despite a family history of breast cancer, Cappon’s mother has had the disease twice, Cappon’s family and gynecologist thought the lump was more than likely just a cyst.

Click here for a video interview with Colleen Cappon

After receiving a sonogram, which revealed the lump was not a cyst, Cappon was referred to a breast health surgeon in her hometown of Watertown, N.Y., a rural community near the Canadian border.

The surgeon believed Cappon’s lump to be fibroadenoma, which is nothing more than calcium and fatty tissue. To be sure though, the lump was removed and sent to a lab for identification.

"Luckily, I had a couple of days off of work that week, so I went in,” Cappon said. “It was like this big joke between me and my friends that I was getting this lump taken out. No big deal.”

But it was a big deal. The surgeon called Cappon, a former FOX News intern, after getting the lab results and broke the news to the soon-to-be SUNY Cortland senior.

“I’m really sorry to tell you this, but the lump that we took out was breast cancer.”

It was a phrase no 21-year-old expects to hear.

“I was like, 'What? Seriously? Shut up. Really?'” Cappon recalled. “I couldn’t believe it. She couldn’t believe it. She was going to get it checked again at the lab and make sure they didn’t make a mistake. She said I needed to come in that day and we needed to talk about it because, not only was it breast cancer, but it was a nasty one.”

October is Breast Cancer Awareness Month and Cappon is evidence that all women, regardless of age, are at risk for the disease.

"Twenty-one-year-olds should know there are things that can go wrong, and you don’t have to be scared of it and paranoid about it, but you just need to keep a check on it," Cappon said.

Cappon was ultimately diagnosed with Stage III breast cancer. Worse, the tumor was fast growing and had tripled in size within a span of nine days.

Stage III breast cancer is divided into two subsections, A and B. Stage IIIA describes invasive breast cancer in which the tumor measures larger than five centimeters, or where there is significant involvement of lymph nodes.

Stage IIIB describes invasive breast cancer in which a tumor of any size has spread to the breast skin, chest wall, or internal mammary lymph nodes.

Cappon's tumor was 2.5 centimeters and had spread into her mammary lymph nodes.

But Cappon's prognosis is good and she believes with a little humor and a positive attitude she can beat the disease, according to her close friend, Rachel Bregautit.

"She is just like, 'I'm going to get through this. I'm a strong person. It's just a little obstacle that we're going to get through,'" Bregautit recalled Cappon saying. "I mean, Colleen, she would exercise regularly, eat healthy, but she still got this. She never takes anything for granted and I know that she’s going to get through this."

Not a Young Person’s Disease

Many people think of breast cancer as a disease that affects middle-aged women. And, for the most part, it is, say doctors.

"Breast cancer in women younger than 30 is so rare,” said Dr. Diana Zuckerman, president of the National Research Center for Women & Families, who has not treated Cappon. “I think the media focuses on young women because it’s so shocking when someone in their 20s gets cancer. But what you end up with are women in their 20s and 30s who are terrified that they're going to get cancer and women in their 50s who think they don’t need to worry about it, when the opposite is true."

Of the nearly 200,000 women who will get breast cancer next year, half will be over the age of 61. About 25,000 women will be under the age of 40, said Dr. Marisa Weiss, a Philadelphia oncologist and the founder and president of breastcancer.org.

“It’s still a significant number, but when you compare it to the overall number of women who get breast cancer, it’s a small percentage,” said Weiss, who has not treated Cappon.

Zuckerman said even women with a history of breast cancer in their families are not likely to get the disease in their 20s. Despite a family history, Cappon does not carry the BRCA 1 or BRCA 2 genes that have been linked to the disease.

“We don’t want to terrify young women into thinking their days are numbered while they’re still in their 20s,” Zuckerman said. “But women are getting it younger than ever before. We have some theories on the why; the major belief is that it stems from chemicals in the environment that have similar properties to estrogen. Those hormone disrupting chemicals are in pesticides, in some plastics, and in many cosmetics — even some nail polishes contain these chemicals."

Although most people are exposed to some environmental estrogens, it is believed, said Zuckerman, that some people are more susceptible to their effects. People who are exposed to high levels of hormone disrupting chemicals

Although most people are exposed to some environmental estrogens, it is believed, said Zuckerman, that some people are more susceptible to their effects. People who are exposed to high levels of hormone disrupting chemicals, especially those exposed at very young ages and while still in the womb, are believed to be most at risk.

The Treatment

Once she received the breast cancer diagnosis, Cappon’s doctors told her they’d have go in and remove more tissue from her breasts and lymph nodes, and that she would need radiation and chemotherapy treatments. She also has to go on hormone suppression therapy for five years to stop her ovaries from producing estrogen.

Cappon plans to have a double mastectomy, followed by reconstructive surgery. “When it was first suggested to me, doctors kind of tiptoed around it,” she said. “But if I don’t have it done, I’ll be constantly worrying about it and the chances of it coming back.”

About 75 percent of women diagnosed with breast cancer do not need mastectomies, said Zuckerman. But even if Cappon had a less-advanced stage of breast cancer, Zuckerman said she would more than likely recommend a mastectomy.

“If you have a 21-year-old with real breast cancer, a mastectomy might be appropriate because more than likely the cancer is very aggressive,” she said. “Usually if a woman has a lump that she can feel or see, that lump has been growing for years.”

On the bright side, Zuckerman said surgeons have new techniques that allow them to reconstruct breasts that look and feel more natural.

“The woman won’t have any feeling in them, unfortunately,” she said.

But, like everything else about her illness, Cappon is also taking losing her breasts in stride.

"So I'll get new boobs for Christmas," she said. "A present not many people get."

Cappon’s biggest fear was losing her ability to have children and is exploring egg-harvesting as an option.

“I know that I eventually do want kids, so that was something I was pretty upset about,” she said. “I think that in five years from now, when I’m done with the hormone therapy, there’s like a 70 percent chance that my ovaries will just wake right back up and be OK, ready to go. But there’s a 30 percent chance that they’ll just stay asleep and not want to do anything.”

The Fight

Cappon returned to college in September, anxious to finish out her senior year. She must drive an hour-and-a-half home every other week for her treatments.

“I told the professors that I have for my classes and they’ve been awesome,” Cappon said. “More than helpful, willing to do whatever it is they need to do.”

Although she was forced to shave off her blonde hair and begin wearing a wig once she started treatments (Cappon donated her hair to an organization that makes wigs for women battling cancer), she’s determined to continue life as a normal college student: riding her bike around campus and even occasionally going out drinking with her friends on the weekends. She’s also planning a spring break trip.

“I hate to say the drinking thing, but I’m 21 and I’m not a huge, huge drinker,” she said. “But it was hard the first time. I had one treatment and I went out with my friends drinking. The next morning, I had never been so hung-over in my life. It's like my poor body is trying to fight this and look what I do, it hates me.”

Cappon also hopes to be an advocate and to educate other young women about the dangers of breast cancer. “I don’t want them to have to feel the way that I felt: just totally in the dark, dumbfounded, in disbelief that this could even happen,” she said.

But Cappon is confident she will beat breast cancer. "I just feel like I wouldn’t get dealt something that I couldn’t handle and I thought I was pretty kick-ass before, now, after this, I’m going to be really kick-ass," she said.

To read more about Cappon and what her doctors say about her prognosis, visit Foxnews.com/health Monday, Oct. 15.

Additional reporting by Melissa Browne, Foxnews.com video producer