B7-H3 AS A BIOMARKER FOR DIAGNOSING THE PROGRESSION AND EARLY LYMPH NODE METASTASIS OF CANCER

1 . A method for diagnosing the progression of cancer with a high propensity of primary tumor metastasis to the lymph node or distant site comprising:

obtaining a cancer tissue sample from a cancer patient; and

determining an expression level of B7-H3 present in the tissue sample; and

diagnosing the progression of the cancer having a high propensity of primary tumor metastasis to the lymph node or distant site based upon the expression level, wherein an increased expression level correlates with an increased probability of having regional lymph nodes or organ site that are positive for metastases.

2 . The method of claim 1 , wherein the cancer tissue sample is a primary or metastatic tumor tissue specimen.

3 . The method of claim 2 , wherein the expression level of B7-H3 is determined by immunohistochemistry.

4 . The method of claim 2 , wherein the expression level of B7-H3 is determined by a direct qRT-PCR assay.

5 . The method of claim 1 , wherein the cancer tissue sample is a blood specimen from a cancer patient.

6 . The method of claim 5 , wherein the expression level of B7-H3 is determined by an anti-B7-H3 magnetic bead capture assay.

7 . The method of claim 5 , wherein the expression level of B7-H3 is determined by a direct qRT-PCR assay.

8 . The method of claim 6 or 7 , wherein the assay detects B7-H3 expressed on circulating tumor cells.

9 . The method of claim 1 , wherein the cancer is selected from the group consisting of melanoma, breast cancer, gastrointestinal cancers such as gastric cancer, colorectal, periampullary, pancreatic, liver cancer.

10 . The method of claim 1 , wherein the cancer is melanoma.

11 . The method of claim 1 , wherein the cancer is breast cancer.

12 - 20 . (canceled)

21 . A method for detecting circulating tumor cells in a cancer patient, comprising:

obtaining a bodily fluid sample from a cancer patient;

performing an assay to detect the presence of a B7-H3 expression level in the bodily fluid sample, wherein a higher expression level of B7-H3 correlates with a higher number of circulating tumor cells.

22 . The method of claim 21 , wherein the bodily fluid sample is selected from the group consisting of blood, cerebrospinal fluid (CSF), spinal fluid, synovial fluid, ascetic fluid, pericardial fluid and peritoneal fluid.

23 . The method of claim 21 , wherein the assay is qRT-PCR.

24 . The method of claim 21 , wherein the assay is an anti-B7-H3 magnetic bead capture assay.

25 . A method for treating a cancer with a high propensity of primary tumor metastasis to the lymph node or distant site comprising:

obtaining a bodily fluid sample from a cancer patient;

detecting the presence of a population of B7-H3-positive CTC in the bodily fluid; and

administering a therapeutically effective amount of a pharmaceutical composition, the pharmaceutical composition comprising a B7-H3 ligand conjugated to a cytotoxic drug;

wherein the pharmaceutical composition kills B7-H3 circulating tumor cells and prevents metastasis.

26 . The method of claim 25 , wherein the bodily fluid is selected from the group consisting of blood, cerebrospinal fluid (CSF), spinal fluid, synovial fluid, ascetic fluid, pericardial fluid and peritoneal fluid.

27 . The method of claim 25 , wherein detection of a population of B7-H3-positive CTC is accomplished by performing qRT-PCR on the bodily fluid sample.

28 . The method of claim 25 , wherein detection of a population of B7-H3-positive CTC is accomplished by performing an anti-B7-H3 magnetic bead capture assay.

29 . The method of claim 25 , wherein the B7-H3 targeted therapy is a B7-H3 ligand conjugated with a cytotoxic drug.