From the Guidelines
In situ cancer refers to cancer cells that remain confined to their site of origin without invading surrounding tissues, and it is essential to detect and treat these early-stage cancers to prevent progression to invasive forms. This early-stage cancer is characterized by abnormal cells that have not yet spread beyond the epithelial tissue where they first developed. Common examples include ductal carcinoma in situ (DCIS) in the breast and cervical carcinoma in situ, as discussed in the guidelines for the management of DCIS by the American College of Radiology, the American College of Surgeons, the College of American Pathologists, and the Society of Surgical Oncology 1. In situ cancers are generally considered pre-invasive or pre-malignant conditions with a high cure rate when detected and treated early.
Key Characteristics of In Situ Cancer
- The cancer cells have not broken through the basement membrane that separates them from deeper tissues
- The cancer is confined to the site of origin
- The cancer has not spread to other parts of the body
- The cancer is considered pre-invasive or pre-malignant
Importance of Early Detection and Treatment
Treatment typically involves surgical removal of the affected area, sometimes followed by radiation therapy depending on the cancer type and location. Regular screening tests are crucial for detecting these early-stage cancers before they progress to invasive forms, which have a less favorable prognosis due to their ability to spread to other parts of the body. The term "in situ" literally means "in position" or "in place," indicating that the cancer cells have not invaded surrounding tissues.
Guidelines for Management
The management of DCIS should be based on a thorough evaluation of the extent and character of the patient's disease, including clinical, mammographic, and pathologic evaluation, as recommended by the American College of Radiology, the American College of Surgeons, the College of American Pathologists, and the Society of Surgical Oncology 1. This evaluation is necessary to determine the patient's suitability for breast conservation with or without irradiation or the necessity of mastectomy.
Conclusion is not allowed, so the answer will be ended here.
From the Research
Definition of In Situ Cancer
In situ cancer refers to an early stage of cancer where the tumor cells are confined to the original site and have not invaded surrounding tissues [ 2, 3, 4 ].
Characteristics of In Situ Cancer
The clinical expression of in situ cancer can vary widely, but it is usually occult, meaning it is not visible or symptomatic [ 2 ]. In situ cancer can be diagnosed using minimally invasive techniques [ 2 ].
Types of In Situ Cancer
There are two main types of in situ breast cancer:
- Ductal carcinoma in situ (DCIS), which is considered a preinvasive stage that may eventually evolve into invasive cancer [ 3, 4, 5, 6 ]
- Lobular carcinoma in situ (LCIS), which is viewed as a marker of risk for subsequent carcinoma [ 2, 4 ]
Treatment of In Situ Cancer
Treatment options for in situ cancer vary depending on the type and severity of the disease. For DCIS, treatment options include mastectomy or breast-conserving surgery, which may be supplemented with radiotherapy [ 2, 3, 5 ]. For LCIS, treatment is generally limited to close follow-up [ 2 ].
Prognosis and Risk
In situ breast carcinoma has a favorable prognosis with appropriate management [ 4 ]. However, there is a risk of overtreatment, particularly for DCIS, as many lesions remain indolent and may not progress to invasive cancer [ 5, 6 ].