Does cassava help to control prostate cancer

Article · January 2012with33 Reads
Case report Open Access
Does cassava help to control prostate cancer? A case
report
Anuruddha M Abeygunasekera
1† *
and Kalana H Palliyaguruge
1†
*Correspondence: amabey@sltnet.lk
These authors contributed equally to this work.
1
Urology Department, Colombo South Teaching Hospital, Kalubowila, Dehiwela, Sri Lanka.
Abstract
Natural products are getting popular among patients as therapy for many diseases. However these remedies should be
proven scientically as some may be hazardous with no proven benets. Cassava root, used as a carbohydrate rich food
in many countries is promoted as a cure for prostate and bladder cancer. Serum prostate specic antigen is a sensitive
tumour marker which corresponds to the activity of malignant cells in patients with acinar adenocarcinoma of prostate.
We report a patient with hormone-resistant prostate cancer whose serum PSA level continued to rise despite
consumption of large quantities of boiled roots of cassava indicating its ineectiveness in controlling the prostate cancer.
ough this is a single case, it provides guidance to health care workers who look aer patients with castration-resistant
prostate cancer in the absence of more comprehensive research on cassava and its eectiveness on prostate cancer.
Keywords: Tapioca, manioc, herbal medicine, prostatic carcinoma, treatment
© 2013 Abeygunasekera et al;
licensee Herbert Publicaons Ltd. This is an open access arcle distributed under the terms of Creave Commons Aribuon License
(hp://creavecommons.org/licenses/by/3.0),This permits unrestricted use, distribuon, and reproducon in any medium, provided the original work is properly cited.
Background
Medicinal plants play a vital role in the development of
new drugs. There is an increasing interest in remedies
for illnesses based on natural products. However these
remedies should be proven scientifically as some tend
to make unsubstantiated claims of efficacy based on
emotions related to illnesses which do not have effective
therapy based on established medical practice. Cassava,
also known as tapioca or manioc is promoted widely as
a cure for cancer in the electronic and printed media
especially for bladder and prostate cancer [1,2]. Excess
consumption of cassava based on unscrupulous reports
can be hazardous [
3
]. We describe the outcome of a patient
with hormone-resistant prostate cancer who tried cassava
to control his malignancy.
Case report
A 65 year old man was diagnosed of having adenocarcinoma
of prostate with a Gleason score of 3+3 in 2002. The CT and
isotope bone scans did not show evidence of metastases
(T
2c
N
0
M
0
stage). The serum prostate specific antigen (PSA)
was 11.5 µg/l. He underwent external beam radiotherapy
(70 Gy) and bilateral orchidectomy. The PSA decreased to a
nadir of 0.02 µg/l and remained around that level till 2008
when it started rising slowly suggesting local recurrence
(Figure 1). When PSA was 3.4 µg/l, he had a repeat biopsy
which showed an adenocarcinoma of Gleason score 3+5.
Flutamide 250mg three times a day brought down the
PSA to 0.75 µg/l. After 2 years it started rising gradually
and discontinuation of the anti-androgen (flutamide),
caused a drop in the PSA suggestive of anti-androgen
withdrawal response. Six months later when the PSA
started rising again and reached 9.5 µg/l, oral fosfestrol
(‘Honvan’) 240 mg/ day was started. His serum testosterone
level was below 50 ng/dl, which is the cut-off level to
diagnose hormone-resistant (castration-resistant) prostate
cancer. With oral fosfestrol, the PSA fell to 1.86 µg/l and
the therapeutic response lasted for one year. When the
PSA rose to 10.4 µg/l in March 2012, he responded to a
combination of ketoconazole (200mg three times a day)
and hydrocortisone (20mg in the morning and 10mg in
the evening). The PSA fell to 0.13 µg/l in six weeks.
At this time the patient came to know through the
media about consuming cassava in the diet to control
cancers and started consuming 150 g of boiled cassava
root (sweet variety) three times a day [
2
]. He stopped
all the medications and consumed boiled cassava root
diligently in measured amounts for three weeks. At the
end of the three weeks PSA rose to 4.05 µg/l. A week
later it increased further and reached 4.95 µg/l despite
continuing to consume cassava. He restarted ketoconazole
and hydrocortisone and the PSA level dropped to 3.24
µg/l after one week. All PSA levels were done in the same
laboratory and there was no clinical or microbiological
evidence of urinary infection during the period when the
patient consumed cassava.
Discussion
Cassava also known as manioc and tapioca (Manihot
esculenta Crantz), has been used as a food for centuries. It
Journal of
Pharmaceutical Technology
Drug Research
&
Page 1
Abeygunasekera et al. Journal of Pharmaceutical Technology & Drug Research 2013,
http://www.hoajonline.com/journals/jptdr/content/pdf/volume/2/3.pdf
2
doi: 10.7243/2050-120X-2-3
originated in South America and was introduced to Africa by
the Portugese in the sixteenth century [4]. It is a rich source
of carbohydrates and grows in dry conditions with little
water. Today it is consumed by millions of people around
the world [
5
]. There are two types of cassava – sweet and
bitter varieties. Sweet variety is preferred by consumers as
it is more palatable while the bitter variety is preferred by
farmers as it is more resistant to pests. Both cassava root
(tuber) and leaves are used as herbal medicine especially
in Africa and South America [6]. Although it has not been
used in the past by native physicians of India and Sri Lanka
in their traditional medical therapies like ‘Ayurveda’ [
7
], in
recent times boiled roots of cassava is being promoted
as a potential cure for prostate and bladder cancer in Sri
Lanka [1,2].
Linamarin, the main cyanogenic glucoside in manioc
has been shown to cause toxicity to malignant cell lines [
8
].
A nested case control study conducted in India to identify
the effect of dietary factors on causation of breast cancer
using food frequency questionnaires has shown that
consumption of tapioca is associated with a decreased
risk of developing breast cancer [9]. The cyanogenic
glucosides (linamarin and lotaustralin) in cassava leads
to the production of amygdaline or vitamin B-17 which is
claimed to kill cancer cells by those who promote cassava
as an anti-cancer agent [
2
]. However two case-control
studies from India have shown that cassava consumption
is associated with a higher risk of colorectal and pancreatic
carcinoma [
10
,
11
]. In addition cassava may cause ataxic
polyneuropathy, amblyopia and tropical pancreatitis as
reported in several case reports from India and Nigeria
[11,12]. Therefore it is prudent that we determine both the
safety and efficacy of cassava in treating prostate cancer
before it is promoted as a treatment.
Despite clinical and analytical limitations, PSA is an
effective surrogate marker of cancer activity of already
diagnosed cases of acinar adenocarcinoma of prostate
[
13
]. This patient’s cancer was treated with accepted and
proven forms of treatment in a stepwise manner and as
expected, PSA levels varied accordingly with each form
of treatment. This predictable response was confirmatory
of its applicability as an efficient marker of malignant cell
activity of this patient. However the PSA level rose while
on cassava indicating its ineffectiveness in controlling
the cancer. It appears that consumption of cassava in
large quantities in the diet has no biochemically evident
therapeutic benefit in castration-resistant prostate cancer.
Anti-androgen withdrawal is a potential therapeutic
manoeuvre for patients with progressive prostate carcinoma.
About 19% of patients with prostate cancer experience a
progression-free period of over one year after cessation
of anti-androgens [14]. Some patients who discontinue all
medications including anti-androgens andstart consuming
cassava may experience a reduction in PSA due to this
phenomenon but may attribute it to the consumption
of cassava.
A single case may not be adequate to test a hypothesis.
However in the absence of scientific publications about
the effects of cassava on prostate cancer, this scientifically
tested case would act as a basis of evidence that can be
used by health care workers who look after patients with
castration-resistant prostate cancer as well as by patients
with the disease until further research is done and better
evidence is available.
Competing interests
The authors have no financial or other interests related to this
article.
Authors contributions
AMA conceived the idea, performed the literature search,
wrote the manuscript and managed the patient. KHP
helped with the literature search and management of the
patient. Both read and approved the final manuscript.
Acknowledgements
We thank the patient for agreeing to share his
clinical details with the scientific community.
Publication history
Received: 27-Nov-2012 Revised: 16-Dec-2012
Accepted: 22-Dec-2012 Published: 10-Jan-2013
References
Figure 1. Prostate-specic antigen levels and events
References
1. Daily Mirror. | Website
2. The Healing Herbs and Juice Guide. | Website
3. BP Kamalu: The adverse eects of long-term cassava (Mani-
hot esculenta Crantz) consumpon. Int J Food Sci Nutr 1995,
46:65-93. | Arcle | PubMed
4. Fauquet C, Fargelle D: African cassava mosaic virus: Eology,
Epidemiology and Control. Plant Diseases 1990, 74: 404-411.
| Pdf
5. Dimensions of Need: An atlas of food agriculture. Food and
Agriculture Organisaon of the United Naons. 1995
6. CN Tsumbu, G Deby-Dupont, M Tits, L Angenot, T Franck, D
Serteyn and A Mouithys-Mickalad: Anoxidant and anradi-
cal acvies of Manihot esculenta Crantz (Euphorbiaceae)
Page 2
Abeygunasekera et al. Journal of Pharmaceutical Technology & Drug Research 2013,
http://www.hoajonline.com/journals/jptdr/content/pdf/volume/2/3.pdf
3
doi: 10.7243/2050-120X-2-3
leaves and other selected tropical green vegetables inves-
gated on lipoperoxidaon and phorbol-12-myristate-13-ace-
tate (PMA) acvated monocytes. Nutrients 2011, 3:818-38. |
Arcle | PubMed Abstract | PubMed Full Text
7. Aygalle J: Sinhalese Materia Medica. India: Navrang, 1917
8. CA Idibie, H Davids and SE Iyuke: Cytotoxicity of puried cassa-
va linamarin to a selected cancer cell lines. Bioprocess Biosyst
Eng 2007, 30:261-9. | Arcle | PubMed
9. P Jayalekshmi, SC Varughese, Kalavathi, MK Nair, V Jayaprakash,
P Gangadharan, RR Nair and S Akiba: A nested case-control
study of female breast cancer in Karunagappally cohort in
Kerala, India. Asian Pac J Cancer Prev 2009, 10:241-6. | Arcle
| PubMed
10. SP Nayak, MP Sasi, MP Sreejayan and S Mandal: A case-
control study of roles of diet in colorectal carcinoma in a
South Indian Populaon. Asian Pac J Cancer Prev 2009, 10:565-
8. | Arcle | PubMed
11. M Mori, M Hariharan, M Anandakumar, M Tsutsumi, O
Ishikawa, Y Konishi, VG Chellam, M John, I Praseeda, R Priya
and M Narendranathan: A case-control study on risk factors
for pancreac diseases in Kerala, India. Hepatogastroenterol-
ogy 1999, 46:25-30. | Arcle | PubMed
12. OS Oluwole, AO Onabolu and A Sowunmi: Exposure to
cyanide following a meal of cassava food. Toxicol Le 2002,
135:19-23. | Arcle | PubMed
13. RR Jurhill, H van der Veen, GJ van Leenders and PC Ver-
hagen: Reducon of serum prostate-specic angen levels
following varicella-zoster infecon and valaciclovir treatment
in prostate cancer. Eur Urol 2009, 56:392-4. | Arcle | PubMed
14. AO Sartor, CM Tangen, MH Hussain, MA Eisenberger,
M Parab, JA Fontana, RA Chapman, GM Mills, D Raghavan and
ED Crawford: Anandrogen withdrawal in castrate-refractory
prostate cancer: a Southwest Oncology Group trial (SWOG
9426). Cancer 2008, 112:2393-400. | Arcle | PubMed Abstract
| PubMed Full Text
Page 3
  • [Show abstract] [Hide abstract] ABSTRACT: Cassava (Manihot esculenta Crantz) is an important dietary staple for more than 500 million people in developing countries. People eat 60% of the cassava produced and one third of the harvest feeds animals. All cultivars of cassava contain the cyanogenic glucoside, linamarin, but in different concentrations. The roots of those cultivars with high cyanogenic content are processed to reduce the level of linamarin, because linamarin is hydrolysed in the intestinal tract of both men and animals by microbial flora and HCN is released. Researchers have implicated the sublethal levels of HCN produced on ingestion in the development of a number of metabolic diseases in both man and animals when cassava-based diets are consumed over a long period of time but the release of HCN cannot fully explain the metabolic effects of ingested linamarin. A significant amount of linamarin remains intact and is excreted in the urine. It appears that the intact linamarin inhibits Na+K+ATPase causing electrolyte imbalance within the cell. This phenomenon is exacerbated by free radicals generated by the hypoxia/normoxia cycles created by cyanide released from linamarin, which cause lipid peroxidation and cell membrane damage. When the supply of endogenous thiosulphate is adequate, cyanide plays a very minor role in the development of lesions. The amount of damage is related to the quantity of linamarin routinely ingested at sublethal levels. There appears to be species differences in the rate of the development of diseases and the intensity.
    No preview · Article · Mar 1995 · International Journal of Food Sciences and Nutrition
  • Preview · Article · Jun 1990 · Plant Disease
  • [Show abstract] [Hide abstract] ABSTRACT: Cassava (Manihot esculenta Crantz) is a known source of linamarin, but difficulties associated with its isolation have prevented it from being exploited as a major source. A batch adsorption process using activated carbon proved successful in its isolation, with ultrafiltration playing a pivotal role in its purification. Thirty-two minutes of contact time was required for 60 g of extract, yielding 1.7 g of purified product. Picrate paper, infra-red and 'HNMR analysis confirmed the presence and structure of linamarin. Cytotoxic effects of linamarin on MCF-7, HT-29 and HL60 cells were determined using the MTT assay. Cytotoxic effects were significantly increased in the presence of linamarase (P-glucosidase), with a 10-fold decrease in the IC50 values obtained for HL-60 cells. This study thus describes a method for the isolation and purification of linamarin from cassava, as well as its cytotoxicity potential.
    No preview · Article · Jul 2007 · Bioprocess and Biosystems Engineering
Show more