Nicole and her girlfriends went for their annual mammogram. It was always more fun to do it in a group. Although they were all in their young 40s and the government is trying to tell them not to have a mammogram till they turn 50, they listened to the advice of their physicians and have been getting screening mammograms since they turned 40. Nicole’s mammogram had some microcalcifications, small pieces of calcium that are deposited from breast tissue. Most often, fibrocystic breast changes can cause calcium deposits, but on occasion, the calcium can be deposited by cancer. Nicole had a core needle biopsy and was told she had Ductal Carcinoma In Situ. Nicole had breast cancer, or so she thought. Her friend Amber, who knows everything, said that Nicole did not have cancer, that DCIS is a benign growth. Well, does Nicole have cancer? Is DCIS cancer?
Yes. DCIS is cancer. DCIS can recur after excision. DCIS can transform into a malignant tumor. Cure rates are as high as 98%, but 2% still succumb to the disease. Thus, DCIS is cancer, but benign cancer, as opposed to malignant cancer, which can spread throughout the body.
The breast is composed of two basic units: lobules that make milk and ducts that transport the milk. It is the cells lining the duct that can turn cancerous. Each cell has an instruction book, composed of its genes, which in turn, are comprised of DNA. It’s as if the instruction book has chapters called genes and the pages are its DNA. The instruction book of the cells lining the breast ducts can become ruined when pages are added, removed, or smudged, like when you pour water on a book. When DNA is added, removed, or “smudged,” the genes become unreadable and are mutated. The instruction book cannot be read properly, and just like teenagers, the breast duct cells cannot follow directions, and the cells act and grow uncontrollably. Uncontrollable growth is the hallmark of cancer.
If these cancer cells, which are growing uncontrollably, stay inside the duct, they are referred to as Ductal Carcinoma In Situ (DCIS). They are ductal cells that have become cancer, but they have remained in their original place (in situ) and are thus benign cancer. When the cancer cells learn how to eat through the walls of the duct and invade the breast stroma(the tissue surrounding the ducts), then cancer has transformed to malignant cancer, which has the potential to spread throughout the body. Benign cancer, like DCIS, does not have the potential to spread throughout the body, which is why cure rates can be as high as 98%. Benign means “born good”, as in beneficial, while malignant means “bad,” like Maleficent from Sleeping Beauty.
DCIS is not malignant cancer; it is benign cancer. DCIS remains inside the duct, in its original place (in-situ), but DCIS can transform into malignant cancer, and therefore, we need to treat DCIS very carefully and appropriately. We must respect DCIS. Still, not all DCIS needs treatment. Some DCIS only requires local excision. Many of the DCIS cancers will never cause trouble as they will neither spread nor grow very big. But we do not know which DCIS will behave in a manner that is not a threat. A low-grade DCIS that is less than 1cm in size is probably the kind DCIS that will never be a threat. But DCIS that is not low-grade or is larger than 1cm may have a chance to cause trouble and should be treated appropriately. One day, we will be able to distinguish between low-risk DCIS and high-risk DCIS. But not today.
DCIS is cancer. But it is not malignant.
Nicole opted to have the calcifications excised to ensure that no invasive breast cancer was present. There was not any. Nicole had DCIS only. Now she and her surgeon had to discuss the next step in her treatment: observe her breast, radiate her breast, or remove her whole breast.