Which tumors are prone to lymph node metastasis?

Tumors that are prone to lymph node metastasis generally include breast cancer, gastric cancer, lung cancer, colorectal cancer, and thyroid cancer. Detailed analysis is as follows:

1. Breast cancer: Breast cancer cells easily invade surrounding lymphatic vessels and can metastasize early to ipsilateral axillary lymph nodes. Some patients present with enlarged axillary lymph nodes at the time of diagnosis. In advanced stages, metastasis may also occur to lymph nodes above the clavicle, internal mammary regions, and other areas. The status of lymph node metastasis is a key factor in determining disease staging and treatment strategies.

2. Gastric cancer: Gastric cancer cells commonly spread via perigastric lymphatic channels. Frequent sites of metastasis include lymph nodes along the lesser and greater curvatures of the stomach, followed by further spread to lymph nodes near the celiac artery and hepatic hilum. The extent of lymph node involvement is closely related to prognosis—more extensive metastasis typically correlates with greater treatment difficulty.

3. Lung cancer: Certain types of lung cancer, such as squamous cell carcinoma and adenocarcinoma, are particularly prone to lymph node metastasis. Hilar lymph nodes are common early sites of metastasis. As the disease progresses, metastasis may extend to mediastinal and supraclavicular lymph nodes. Some patients first seek medical attention due to enlarged supraclavicular lymph nodes, leading to the discovery of a primary lung tumor upon further investigation.

4. Colorectal cancer: Colon cancer tends to metastasize to pericolic and paravascular mesenteric lymph nodes, while rectal cancer often spreads to perirectal and inguinal lymph nodes. The presence and extent of lymph node metastasis influence surgical planning; if metastasis is widespread, preoperative adjuvant therapy may be required to reduce tumor burden before surgery.

5. Thyroid cancer: Papillary thyroid carcinoma is the type most likely to undergo lymph node metastasis. Common sites include central and lateral cervical lymph nodes. Even when the primary tumor is small, lymph node metastasis may already be present. Therefore, patients with thyroid cancer routinely require evaluation of cervical lymph nodes.

When unexplained lymphadenopathy occurs, prompt medical evaluation is necessary to determine the possibility of tumor metastasis. After a cancer diagnosis, patients should complete recommended lymph node assessments to define the extent of metastasis. Regular follow-up examinations of lymph nodes after treatment are essential for monitoring disease progression and preventing delays in subsequent therapy.