Page 98 - Bio Engineering Approaches to Cancer Diagnosis and Treatment

96 CHAPTER 4 Immunotherapy

blood vessel and move into tumor cells environment. Finally, T cells lead to tumor cell
apoptosis.
Immunotherapy methods include cancer vaccines, antibodies to destroy cancer
cells, immune regulatory molecules, cell-based therapies [72].
Immunotherapy is an efficient method of combating tumor cells, and it can be
used in combination with other common therapies such as chemotherapy and radia-
tion therapy. Although some failures have been recorded in the history of cancer vac-
cinations, they are still considered to be one of the most highly developed fields in
immunotherapy [73]. Most recently, personalized vaccines have provided scientists
with new approaches in cancer vaccinations [74].
There are two different approaches in cancer vaccination: (1) prevent healthy
people to get cancers (scientists have developed vaccines against HPV and Hepati-
tis B) and (2) treatment of patients with cancer (therapeutic vaccines stimulate the
immune system to fight against cancer) [73].
The early stages of cancer immunotherapy, pioneers primarily focused on mela-
noma which leads them to achieve some noticeable results, as an example on mela-
noma: a phase I trial on melanoma lysates in combination with adjuvant (DETOX)
administrated on 22 patients, and showed low toxic effects [75]. Over time, valuable
improvements in cancer vaccine technology resulted in tremendous vaccines on the
basis of DC vaccine, peptide/protein vaccine, viral vaccines, tumor cell vaccine as
well as DNA and mRNA vaccines [70,73,76].
From 1995 to 2004, NCI Surgery Branch administrated over 500 vaccines for the
treatment of approximately 440 patients who suffered from metastatic cancer, and
the investigations were mostly centralized on the basis of peptide and viral vaccines
which resulted in a major impact on those patients [77].
Although recent researches on cancer vaccination have reached to phase II and
phase III clinical trial, the usage of therapeutic cancer vaccines did not represent clear
usefulness in the patients who suffer from cancer and it may be useful in premalignant
or low residual disease. Hence, combination therapy is of a great concern that can to
say that, the combination of vaccines along with other methods, including immune
checkpoint blockade, chemotherapy, radiotherapy and adoptive cell transferring have
considered to be more efficient [78]. Fig. 4.13 represents the following discussions.

4.6.1 Main strategies in cancer vaccine production
Scientists focused on different methods to prepare cancer vaccines, there are five
main strategies in cancer vaccine technology, including:
• Dendritic cell vaccine
• Peptide vaccine
• DNA/mRNA vaccines
• Tumor cell vaccine
• Viral and bacterial vaccine
Each strategy is discussed further.