In theory yes, but sometimes the HCG is confined to the actual cancer cells
and is not detectable in the blood.
For instance in some cases of prostate cancer it is detectable in the blood
and semen and in others it is not.
Some people have taken pregnancy tests and this has come up positive when
they are not pregnant, it was investigated and they were found to have
cancer.
I don't think it is a reliable blood test for cancers, an 'expert' should
clarify this.
This is a common test used by 'alties' to diagnose cancer, when in fact it
is potentially dangerous as people have been given all clears when they
still have cancer.
(Try googling the trophoblast thesis of cancer for more information - theory
goes that cancer is a false placenta which is killed by proteolytic
enzymes - Gonzalez protocol is based on this)
Anth

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1
1156711&dopt=Abstract

Beta-human chorionic gonadotropin in semen: a marker for early detection of
prostate cancer?

Daja MM, Aghmesheh M, Ow KT, Rohde PR, Barrow KD, Russell PJ.

Oncology Research Centre, Prince of Wales Hospital, Sydney, NSW, Australia.
p.russell@unsw.edu.au

BACKGROUND AND PURPOSE: The beta subunit of human chorionic gonadotropin
(beta-hCG) has been detected in prostate cancer by immunologic and reverse
transcriptase-polymerase chain reaction (RT-PCR) techniques. Recently,
prostate cells have been detected in human ejaculate. This study aimed to
determine if beta-hCG could be detected by RT-PCR from prostatic mRNA
isolated from semen, thus providing a noninvasive procedure for prostate
cancer detection. RESULTS: Expression of beta-hCG in prostate cancer was
confirmed by immunohistochemistry methods. The protein was associated with
low-grade disease: Gleason Score 4 through 7 (N = 26; 69%) but not
high-grade (Gleason 8 or 9) or metastatic (lymph node) disease (N = 12; 8%).
Normal prostate tissue was negative for beta-hCG (N = 14). The beta-hCG
RT-PCR was performed on RNA extracted from seven human prostate cancer cell
lines, which showed variable expression of beta-hCG mRNA. Semen was
collected from patients suspected of having carcinoma of the prostate (N =
94) and from volunteers who were under the age of 30 years and had no family
history of prostate cancer (N = 9). mRNA for beta-hCG was detected in the
ejaculates of 12% of the patients with confirmed prostate cancer (N = 42)
but not in any patients found to be negative for cancer (N = 52). Expression
of beta-hCG mRNA was found in 22% of the control samples. CONCLUSIONS: The
beta-hCG protein is expressed in low-grade prostate cancer and can be
detected by RT-PCR in both prostate cancer cell lines and human ejaculate.
However, the low percentage of detection in ejaculate suggests that beta-hCG
in semen does not provide a useful marker for early prostate cancer
detection.

"HCG may also be produced abnormally by certain tumors,
especially those that develop from an egg or sperm (germ cell
tumors). "

No.  HCG is not normally present in the body (unless you are a
pregnent female) at levels high enough to be detected by the
usual lab tests.  It's only present if the cancer is producing
it, which most often happens when it's a cancer that started with
eggs or sperm precursor cells.

If the HCG-producing cancer has spread into othre tissues, it
will probably still be producing it, but it's not common for a
tumor in the lung, breast or brain to be making it.

Tsu Dho Nimh

This article about hCG, was recently posted here:

[http://abcnews.go.com/sections/primetime/2020/PRIMETIME_010419_abbott_feature.html]

High hCG Levels, False Positives:

"Rufer is among the 10 percent of the population, whose blood contains
natural substances that can interfere with lab tests, and cause results
that are false positive."

-------------------

some quotes:

"I can't have kids," she says, "and I desperately want to have a
family."  Compounding the physical and emotional pain that haunts her
every day, doctors have discovered Rufer never had cancer at all.

Rufer has brought a lawsuit against Abbott Laboratories, one of the
world's largest diagnostic and pharmaceutical companies, ... claiming
that flawed results from their Axsym BHCG pregnancy test led to
unnecessary cancer treatments, including chemotherapy and a
hysterectomy.

High HCG Level

Three years ago, soon after Rufer was married, she went to the doctor
because of irregular bleeding. The doctor took a blood sample for the
Axsym BHCG routine pregnancy test, one of the most common blood
pregnancy tests in the country.

The test results came back positive, showing Rufer was pregnant. But her
doctor could find no baby. Additional Axsym pregnancy tests came back
positive for Rufer, and still there was no indication of a pregancy.

When a woman is pregnant, she produces high levels of a hormone called
beta human chorionic gonadotropin (HCG).

But if there is no baby, the elevated HCG levels can be a sign of a rare
form of cancer, called a "gestational trophoblastic tumor".

If untreated, it can spread rapidly and kill. If treated early with
chemotherapy, it is highly curable.  In fact, early treatment is so
important, that doctors sometimes order chemotherapy, even if there is
no evidence of a tumor.

Rufer was referred to a cancer specialist, at the University of
Washington Medical Center in Seattle, for more extensive tests. Though
scans showed no sign of a tumor, her HCG level continued to be
alarmingly high. Doctors diagnosed her with cancer, and she began
chemotherapy immediately.

Chemotherapy continued for four months, but Rufer's HCG levels on the
Abbott test remained between 250 and 350, while a normal level is less
than five.

She was told she would have to have a hysterectomy.   Tissue samples
after her hysterectomy, showed no evidence of cancer.

At first, her HCG levels dropped, but then went back up. Then, doctors
saw two suspicious spots on her lung scan, so she had additional
surgery. Doctors still found no cancer, and yet her HCG levels remained
elevated.

Then came a stunning relevation: "They ended up finding out that I have
never had cancer," says Rufer. "That this test was faulty from the
beginning, and that I had never had this disease. I had been treated for
no reason at all."

False Positives

Rufer is not the first, to have blood pregnancy test results, indicate a
false positive.

Laurence Cole, a Yale University researcher who published an article
about women who are misdiagnosed with cancer, based on incorrect
pregnancy tests, ... found that Rufer is among the 10 percent of the
population, whose blood contains natural substances that can interfere
with lab tests, and cause results that are false positive.

No lab test is 100 percent perfect, and other companies that make
pregnancy tests measuring HCG, have also shown false positives. But
Cole, who has become an expert witness in cases against Abbott, believes
the company has a greater problem.  "We are still to this day, hearing
about false positive results in the Abbott Axsym test," he says.

Abbott's Response

In numerous statements to ABCNEWS, Abbott insists its test is no more
prone to false positives, than any other test on the market.

----------------

Susan, Su_Texas  my opinions