Understanding Ductal Carcinoma In Situ: An early form of breast cancer that, if caught, can save lives

October is world over recognised as International Breast Cancer Awareness Month.

In India, well over 1,50,000 women are diagnosed with breast cancer every year; a staggering number that has overtaken cervical cancer to become the most common cancer affecting women. Contrary to the western world, where breast cancer is common after the age of 50, the highest incidence of breast cancer in India is between the ages of 40-50 years. More than 70,000 women in India succumb to breast cancer every year – which means that a woman dies of breast cancer every ten minutes in India.

More than 60 percent of breast cancers in India present in the advanced stages and hence, the death rate from breast cancer is also very high. Lack of awareness and the absence of an organised national breast cancer screening programmes are the main reasons accounting for the late presentation.

Image used for representational purpose only. Reuters

Martina Navratilova, a nine-time Wimbledon Singles Champion, was diagnosed with Ductal carcinoma in situ (DCIS), an early form of breast cancer. She is 53 years old and had skipped her annual mammogram for four years. It is recommended to have annual screening mammograms from the age of 40 and up. She admits that her healthy lifestyle and status created a certain complacency when it came to following through with her annual check-ups.

"I went four years between mammograms," she tells in an interview. "I let it slide. Everyone gets busy, but don't make excuses. I stay in shape and eat right, and it happened to me. Another year and I could have been in big trouble." Luckily, the cancer was detected at its earliest stage. She underwent lumpectomy and six weeks of radiotherapy in 2010. Her doctors said that her prognosis was excellent.

Similarly, Sheryl Crow, a well-known singer and nine-time Grammy award winner, and Christina Applegate, another well-known Hollywood actress, were diagnosed with early impalpable breast cancer because of screening mammograms.

What is DCIS?

The breast is made up of ducts, lobules and fatty tissue. Ductal Carcinoma In Situ (DCIS) is an early form of breast cancer where the cancer cells are inside the ducts (that carry milk to the nipple). This is a pre-cancerous condition where the cancer cells have not developed the ability to spread beyond the milk ducts into the normal surrounding breast tissue.

How common is DCIS?

According to the American Cancer Society, about 60,000 Cases of DCIS are diagnosed each year in the United States (accounting for 1 in 5 new cases of breast cancers diagnosed each year). In India, according to the Indian Council of Medical Research (ICMR), about 1,50,000 new cases of breast cancer are diagnosed each year. However, there are no precise statistics on the incidence of DCIS. Due to the lack of awareness and the absence of an organised screening programme, more than 60 percent breast cancers in our country reach to the advanced stage, with most succumbing within a year of being diagnosed.

How does DCIS present?

DCIS does not usually present with any symptom. The vast majority of DCIS cases (more than 80 percent) are detected on screening mammography. DCIS may present with a blood stained discharge from the nipple, a rash around the nipple (referred to as Paget’s disease) or very rarely with a lump in the breast.

How is DCIS diagnosed?

DCIS is detected on routine breast screening assessment. The assessment includes a clinical breast examination by a specialist, breast imaging (mammogram and ultrasound of both breasts) and a needle core biopsy (making it a triple assessment).

The vast majority of DCIS cases (more than 80 percent) can be detected on screening mammography. Reuters

As DCIS very rarely presents with a lump, clinical breast examination is not usually helpful. The mammogram, which is the gold standard for breast screening, usually shows a cluster of abnormal looking (pleomorphic) microcalcifications – tiny specks of calcium which appear as white dots on the mammogram. It must be remembered, however, that not all microcalcifications are cancerous. It requires skill and diligence of a multidisciplinary team to detect DCIS.

Finally, to make a diagnosis, a piece of tissue is removed by doing a core needle biopsy which is done under stereotactic guidance (with the help of mammogram) under local anaesthesia. The other type of needle biopsy, Fine Needle Aspiration Biopsy (FNAC), which is commonly used for palpable breast lumps can be misleading and will not distinguish an invasive cancer (cancer that has spread into the breast tissue) from DCIS. Needle core biopsy is by far the most accurate.

On some occasions, an excision biopsy under general anaesthesia, using a fine guide wire to localise the microcalcifications, may be necessary to obtain a diagnosis, when the cluster of microcalcifications are very tiny and few to get a diagnosis with the needle core biopsy.

How is DCIS graded & what is its significance?

DCIS is graded depending on the appearance of the cells under the microscope and also on how quickly these cells divide. It can be graded as high, intermediate grade and low-grade DCIS. If DCIS is left untreated, the cancer cells may eventually develop the ability to spread from the ducts into the surrounding breast tissue. This is known as an invasive breast cancer. It is less likely for low-grade DCIS to become an invasive breast cancer.

How is DCIS treated?

The aim of treatment is to remove all DCIS within the breast to prevent the development of an invasive breast cancer. The treatment depends on the factors such as the extent of the DCIS within the ducts and the grade of DCIS. Depending on these factors, one of the following treatments is prescribed:

Surgery:

Breast-conserving surgery

Breast surgery is the first-line treatment for DCIS. If DCIS is localised and confined to one area of the breast, breast conservation surgery can be performed. As the cancer can neither be felt by the patient nor by the doctor, a fine guide wire is inserted under local anaesthesia into the breast to pinpoint the abnormal area of the breast. This acts as a guide and the surgeon is then able to remove the area of DCIS along with an area of surrounding normal breast tissue (guide wire assisted wide local excision).

Mastectomy (removal of Breast)

A mastectomy is the surgical treatment of choice if the DCIS affects a large area of the breast; or if it hasn't been possible to get a clear area of normal tissue around the DCIS using breast-conserving surgery; or if there is more than one area of DCIS in the breast (multifocal DCIS).

If a mastectomy is recommended, the patient should be given the option to have an immediate Breast reconstruction at the same time as primary surgery to minimise the psychological and emotional trauma associated with removal of the breast. Generally, the lymph glands in the armpit do not need to be removed as the DCIS has not spread to the breast tissue from the ducts.

Adjuvant treatment:

Further treatment is required following surgery. This is referred to as adjuvant therapy and includes radiotherapy and hormone therapy.

Radiotherapy

If breast conservation surgery has been performed, the standard adjuvant treatment would be six weeks of external beam radiotherapy to the operated breast. If the patient has had Mastectomy, radiotherapy is not required.

Hormone therapy

If the type of DCIS depends on hormone oestrogen to grow (oestrogen receptor positive), hormone therapy in the form of Tamoxifen may be offered. This will also depend on other factors such as the grade of the DCIS.

Chemotherapy

Chemotherapy is not required for the treatment of DCIS.

Is DCIS life threatening and what is the prognosis from DCIS?

No. As the cancer has not spread beyond the milk ducts into any normal surrounding breast tissue, DCIS is not life-threatening. The long-term survival rate for women with DCIS is excellent, close to 100 percent.

P Raghu Ram is the president of the Association of Breast Surgeons of India.