1. A method for detecting a ribonuclease-resistant extracellular human RNA in blood plasma or serum from a human, wherein the ribonuclease-resistant extracellular human RNA is tyrosinase RNA, keratin 19 RNA, prostate-specific antigen RNA, breakpoint cluster region/c-abl oncogene 1 fusion gene (BCR/abl) RNA, carcinoembryonic antigen RNA, p97 RNA, melanoma cell adhesion molecule (MUC 18) RNA, promyelocytic leukemia-retinoic acid receptor alpha gene fusion gene (PML/RAR) RNA, CD44 RNA, Ewing's sarcoma breakpoint region 1-Friend leukemia virus integration fusion gene (EWS/FLI-1) RNA, Ewing's sarcoma breakpoint region 1-v-ets erythroblastosis virus E26 oncogene like fusion gene (EWS/ERG) RNA, acute myelogenous leukemia 1-ETO fusion gene (AML 1/ETO) RNA, beta human chorionic gonadotropin RNA, telomerase RNA, von Hippel-Lindau tumor suppressor (VHL) RNA, mutated in colorectal cancers (MCC) RNA, adenomatous polyposis coli (APC) RNA, deleted in colorectal carcinoma (DCC) RNA, neurofibromin 1 (NF1) RNA, Wilm's tumor gene (WT) RNA, tumor associated glycoprotein-72 (TAG-72) RNA, carbohydrate antigen 19-9 (CA 19-9) RNA, carcinoma antigen-125 (CA-125) RNA, melanoma antigen family A-1 (MAGE 1) RNA, melanoma antigen family A-2 (MAGE 2) RNA, melanoma antigen family A-3 (MAGE 3) RNA, melanoma antigen family A-4 (MAGE 4) RNA, melanoma antigen family A-6 (MAGE 6) RNA, melanosomal matrix protein 17 (GP-100) RNA, heterogeneous nuclear ribonucleoprotein-A1 (hn RNP-A1) RNA, heterogeneous nuclear ribonucleoprotein-A2/B1 (hn RNP-A2/B1) RNA, or heterogeneous nuclear ribonucleoprotein-K (hn RNP-K) RNA, the method comprising the steps of: a) isolating blood plasma or serum from a whole blood specimen of a human, wherein said whole blood specimen contains an active plasma ribonuclease, and wherein said blood plasma or serum contains ribonuclease-resistant extracellular human RNAs complexed to lipid or proteolipid or ribonuclease-resistant extracellular human RNAs that are protein-bound or within an apoptotic body; b) extracting extracellular human RNA from said blood plasma or serum, wherein said extracellular human RNA comprises a ribonuclease-resistant extracellular human RNA present in said blood plasma or serum that is tyrosinase RNA, keratin 19 RNA, prostate-specific antigen RNA, BCR/abl RNA, carcinoembryonic antigen RNA, p97 RNA, MUC 18 RNA, PML/RAR RNA, CD44 RNA, EWS/FLI-1 RNA, EWS/ERG RNA, AML1/ETO RNA, beta human chorionic gonadotropin RNA, telomerase RNA, VHL RNA, MCC RNA, APC RNA, DCC RNA, NF1 RNA, WT RNA, TAG-72 RNA, CA 19-9 RNA, CA-125 RNA, MAGE 1 RNA, MAGE 2 RNA, MAGE 3 RNA, MAGE 4 RNA, MAGE 6 RNA, GP-100 RNA, hn RNP-A1 RNA, hn RNP-A2/B1 RNA, or hn RNP-K RNA; c) producing an amplified product from said extracellular human RNA or cDNA produced therefrom by amplification, wherein said amplification is performed either qualitatively or quantitatively using primers or probes specific for the ribonuclease-resistant extracellular human RNA that is tyrosinase RNA, keratin 19 RNA, prostate-specific antigen RNA, BCR/abl RNA, carcinoembryonic antigen RNA, p97 RNA, MUC 18 RNA, PML/RAR RNA, CD44 RNA, EWS/FLI-1 RNA, EWS/ERG RNA, AML1/ETO RNA, beta human chorionic gonadotropin RNA, telomerase RNA, VHL RNA, MCC RNA, APC RNA, DCC RNA, NF1 RNA, WT RNA, TAG-72 RNA, CA 19-9 RNA, CA-125 RNA, MAGE 1 RNA, MAGE 2 RNA, MAGE 3 RNA, MAGE 4 RNA, MAGE 6 RNA, GP-100 RNA, hn RNP-A1 RNA, hn RNP-A2/B1 RNA, or hn RNP-K RNA, or cDNA thereof; and d) detecting the amplified product, wherein the detection of the amplified product indicates the presence of said ribonuclease-resistant extracellular human RNA in the blood plasma or serum of the human and said ribonuclease-resistant extracellular human RNA is tyrosinase RNA, keratin 19 RNA, prostate-specific antigen RNA, BCR/abl RNA, carcinoembryonic antigen RNA, p97 RNA, MUC 18 RNA, PML/RAR RNA, CD44 RNA, EWS/FLI-1 RNA, EWS/ERG RNA, AML1/ETO RNA, beta human chorionic gonadotropin RNA, telomerase RNA, VHL RNA, MCC RNA, APC RNA, DCC RNA, NF1 RNA, WT RNA, TAG-72 RNA, CA 19-9 RNA, CA-125 RNA, MAGE 1 RNA, MAGE 2 RNA, MAGE 3 RNA, MAGE 4 RNA, MAGE 6 RNA, GP-100 RNA, hn RNP-A 1 RNA, hn RNP-A2/B1 RNA, or hn RNP-K RNA.