Invasive Ductal Carcinoma – Staging and Grading

Obie Editorial Team

When a pathologist receives an invasive ductal carcinoma (IDC) tissue sample from a biopsy, they analyze several factors of the cancer to determine a stage and grade of the cancer. This specifies the size of the cancer, growth rate, and extent of metastasis, or spreading, if applicable.

The stage of a cancer indicates the size of a tumor and the extent of spreading beyond the area it originated. There are five stages of cancer – zero to four. If a ductal carcinoma is staged at a zero, it is called ductal carcinoma in situ (DCIS). DCIS means the cancer is localized to the lobules or milk ducts. Once these cells have been removed via surgery, there is no risk of spreading. For more information on DCIS, check out Definition, Signs, Symptom, and Risk Factors of Ductal Carcinoma In Situ, Diagnosis of Ductal Carcinoma In Situ, and Stages and Grade of Ductal Carcinoma In Situ. Once ductal carcinoma spreads beyond the milk ducts or lobules, it becomes invasive ductal carcinoma, and it is staged at one through four. The earlier stage the cancer is found, the better the chance at successful treatment.

  • Stage One – Tumor is confined within the breast and measures 2 cm or smaller.
  • Stage Two – Tumor has spread to the lymph nodes and/or measures between 2 cm and 5 cm.
  • Stage Three – Cancer may have spread to the lymph nodes and/or other nearby tissues such as the skin or muscle and/or measures greater than 5 cm. 
  • Stage Four – Cancer has metastasized to distant areas of the body. Once a tumor is staged, it must be graded. 

The grading indicates the speed at which the tumor is growing and how it interacts with the normal cells that surround it. The way the cancer cells looks also plays a role. The faster the tumor is growing, the more aggressive the treatment that is needed. There are three grades of cancer – one to three. This is called histological tumor grading. If the entire tumor was removed surgically, the degree of closeness to the edge of the sample removed for analysis is also considered. The grade of a cancer also indicates the likelihood of the cancer to remain after treatment or to return to the affected area.

  • Grade One – The cancer is slow growing and has a lesser chance of spreading further. This is considered ‘low grade’ cancer.
  • Grade Two – The cancer is growing at a moderate rate. This is considered ‘moderate grade’ cancer, and a more aggressive treatment is suggested.
  • Grade Three – The cancer is aggressive and fast growing, and it has a greater chance of spreading to surrounding tissue or throughout the body. This is considered ‘high grade’ cancer, and it requires the most aggressive treatment.

Knowing the stage and grade of the cancer enables your treatment team to develop the most effective treatment plan for your type of cancer without using treatment that will cause more side effects than necessary. Although almost all forms of cancer treatment have unpleasant side effects, the stronger the treatment, the stronger the side effects will usually be.

The other factor that plays a role in the overall picture of your cancer is the hormone receptor status . You can read more about that at Hormone Receptor Status of Invasive Ductal Carcinoma.

My cancer was stage three, grade two, so I underwent the most aggressive chemotherapy available due to the size and invasive status of my tumor. The side effects were numerous; however, they were not unbearable, and my doctor did a great job providing effective side effect management.