Quadrantectomy is a surgical procedure for the breast-conserving removal of breast cancer. This method is one of several breast-conserving therapies (BET). There are some requirements for performing this procedure.
What is quadrantectomy?
Quadrantectomy is a surgical procedure for the breast-conserving removal of breast cancer. In the seventies, the Italian surgeon Umberto Veronesi developed the quadrantectomy, a new surgical procedure for breast-conserving therapy. In this procedure, he removed the area of the breast that contained the tumor. Since only the affected quarter of the breast is excised in this method, he referred to the procedure as quadrantectomy. In this context, the term quadrant stands for quarter. In comparison, the entire breast is removed in a mastectomy. Therefore, quadrantectomy is also called partial mastectomy or segmental mastectomy by some physicians. However, in addition to quadrantectomy, breast-conserving therapies include lumpectomy and segmental resection. In both of these procedures, only the tumor and up to 2 cm of healthy tissue is removed, and especially in segmental resection, the nipple is still removed. Quadrantectomy is now a standard method of breast cancer treatment, along with the other two breast-conserving therapies.
Function, effect, and goals
Quadrantectomy as a breast-conserving therapy was introduced alongside the other two BET procedures after it became clear that removal of the entire breast was not always necessary for a malignant tumor. However, with mastectomy, women often suffer psychologically from the removal of the entire breast. Today, therefore, breast-conserving surgery is the standard method when removal of the entire breast is not necessary. However, which procedure is used for BET is probably up to the individual surgeons on the one hand and also depends on the size and extent of the tumor to be removed. For example, BET including quadrantectomy is indicated in the presence of breast carcinoma or DCIS (ductal carcinoma in situ). Many studies have demonstrated that BET for malignant breast carcinoma has the same effect on overall survival as mastectomy in most cases. In the case of DCIS, the cancer is even limited and only affects the milk duct system. Here, even a BET with a resection margin of ten millimeters in healthy tissue leads to safe control of the tumor. However, there are also certain requirements for a BET including quadrantectomy. There must be a small delineated tumor that is no larger than four centimeters. The tumor must not be with skin involvement. There must still be an adequate breast-to-tumor ratio. The axillary lymph nodes must not yet be affected according to the palpation findings. There must be a tumor-free resection margin of at least one millimeter in the presence of breast carcinoma. Absolute contraindications according to the guidelines of the “Deutsche Krebsgesellschaft e. V.” are multicentric carcinomas, carcinomas with inflammatory processes, a poor tumor-to-breast ratio and the impracticability of radiation. After a distinct preoperative diagnosis, the decision is made whether a BET procedure can be used and, if so, which one. Quadrantectomy involves removal of the affected quadrant with the appropriate skin spindle. If the laterocranial quadrant (laterally above) is affected, it may also be necessary to remove the associated axillary lymph nodes or sentinel lymph nodes. If these are not yet affected, the other lymph nodes do not need to be removed either. This is because the sentinel lymph nodes are always the first to be reached by the tumor cells. Quadrantectomy is often combined with other therapeutic methods such as removal of axillary lymph nodes and radiotherapy. This combination is also referred to as QUART. After removal of the tumor, a fine tissue examination of the frozen section is performed to ensure complete removal of the tumor. If not all tumor tissue has been removed, follow-up surgery is required. The quadrantectomy is followed by follow-up therapy with radiation, chemotherapy or antibody therapy. During follow-up, mammograms should be taken every six months for the next three years. This also includes examination for adverse drug reactions.
Risks, side effects and dangers
Quadrantectomy, like all other surgical procedures, also carries risks and complications. It happens that not all tumor cells were removed. Then a recurrence may occur within the next five years. It is also possible that tumor cells have already spread via the lymph glands and are already forming metastases. Furthermore, inflammatory reactions due to infections are also possible after the operation. This applies to both the wound cavities and the scars. As with any operation, thrombosis in the lower extremities with the risk of pulmonary embolism can occur in rare cases. Postoperative bleeding may also occur, occasionally requiring surgical hemostasis. In quadrantectomy, unlike segmental resection, the nipples are usually preserved. An exception to this is central quadrantectomy. Nevertheless, deformities or asymmetries may occur after the procedure. The challenge in these cases is to correct the cosmetic deficits. One option is to use an autologous graft. In this case, the patient’s own tissue is used immediately after surgery to compensate for the asymmetries. A skin-muscle graft of the large back muscle (Musculus latissimus dorsi) has proven successful in this case. Unlike mastectomy, however, quadrantectomy leaves the breast intact, although follow-up corrections are sometimes necessary. A long-term study over 20 years has also shown that quadrantectomy followed by radiation therapy and mastectomy with total breast removal have equal long-term survival rates.
