The present invention concerns a method for in vitro diagnosis of cancer, in particular breast, thyroid or lung cancer, which consists in determining the presence of ProNGF in a biological sample derived from a patient suspected of suffering from cancer, in particular breast, thyroid or lung cancer. Said method may be used for early diagnosis, screening, therapeutic follow-up, prognosis and for diagnosing relapses in cancer and in particular breast, thyroid or lung cancer.The present invention also concerns the use of a ProNGF inhibitor for preparing a drug, said drug being in particular useful for blocking remote dissemination and cell invasion in patients suffering from cancer, in particular breast, thyroid or lung cancer.The invention is applicable in the field of diagnosis and therapeutics.