1. Principles of
Medical Oncology
Dr Varun Goel
MEDICAL ONCOLOGIST
RAJIV GANDHI CANCER INSTITUTE, DELHI

2. BASIC TENETS
• Cancer Treatment is multidisciplinary
• The suspicion of cancer is based on clinical acumen
• Diagnosis is based on examination of tissue
samples

3. BASIC TENETS
• Oncology care is for life
• Early stage cancers are more curable than late
stage
•Best treatment is often found in clinical trials

4. CLINICAL ACUMEN
• Cancer, like Syphilis, is the "Great Masquerader“
must be considered in every d/d
• No symptom should be attributable to cancer
without persuasive evidence
eg: Pulmonary insufficiency
Meningoencephilits
Unexplained pain

5. Proving the diagnosis
• Cytology from stomach, cervix, bronchus
•Biochemical markers
βhCG, Alfa fetoproteins, CA19-9, CA125
• Histological proof
• Always aim to have histological diagnosis

6. Laws of Therapeutics-Loeb
• If what you are doing, is doing good, keep
doing it.
• If what you are doing, is not doing good, stop
doing it.
• If you do not know what to do, do nothing.
• Never make the treatment worse than the
disease.

7. ………………keep doing it.
 Physician measures effect of intervention on both
tumor and host.
Continue administering a highly active induction
treatment?
• Eg: in childhood leukemia an induction
treatment followed by shift to maintenance
therapy with different agents experienced
long term remissions.
 First law of Loeb does not always apply to cancer

8. ………………..stop doing it.
• No therapeutic response in 8 weeks of treatment
• A third month is unlikely to be beneficial
 Exceptions
• Therapies that work slowly
• Tumor stasis therapies

9. • Hippocratic admonition
"Primum non nocere“(first do no harm)
• Curative and subcurative oncology is toxic
• Attempts to abrogate toxicity by reducing
dose will result in a failed regimen

10. …………….do nothing"
• counsels against uninformed action.
• A rush to judgment or, worse, a rush to do
something, anything, can be disastrous
-except oncological Emergency

11. •Proper goal is
"Maximal life at Maximal quality"
•Never make the treatment worse than
the disease.
• In cancer, the dictum is "Primum
succerere" (first hasten to help)

12. Basic Principles
CHEMOTHERAPY
1.Primary Induction treatment- for advanced
disease or for cancers for which there are no
other effective treatment approaches
2.Adjuvant treatment
Adjuvant chemotherapy is used to treat patients
known to be at high risk of recurrence after initial
local therapy (surgery, radiation) has removed
all evidence of disease

13. Intent of Therapy
 CURATIVE
 PALLIATIVE

14. Curative chemotherapy
• High dose chemotherapy
• Certainty of severe toxicity
• Treatment given to the point of toxicity

15. Cancers CURABLE with Chemo
therapy
 Choriocarcinoma
 ALL of childhood
 Hodgkin's disease
 Burkitt's lymphoma
 APML
 Large Follicular cell lymphoma
 Hairy cell leukemia
 Embryonal cell carcinoma of testis

16. SUBCURABLE Cancers
 Wilm's tumor
 Osteosarcoma
 Ewing's sarcoma
 Embryonal rhabdomyosarcoma
 Small cell carcinoma of lung

17. Palliative chemotherapy
• Palliative chemotherapy is given without curative intent,
but simply to decrease tumor load and increase life
expectancy. For these regimens, a better toxicity profile
is generally expected.
• Minimising potential toxicity is the goal
• Try not to compromise on quality of life
• Dose reduction to avoid toxicity is permissible

18. Adjuvant Chemotherapy
• Adjuvant chemotherapy is used to treat patients
known to be at high risk of recurrence after
initial local therapy (surgery, radiation) has
removed all evidence of disease
• In addition to surgery/radiotherapy
• Goal – to eradicate micrometastases
• Reduce local and systemic recurrence
• Improve overall survival

19. Proven role of adjuvant CT
 Breast  NSCLC
 Ovary  Head and Neck
 Cervix  Wilms' tumor
 Colon  Osteogenic
 Gastric sarcoma

20. Neo-adjuvant
• Neoadjuvant therapy is given after a histological
diagnosis has been established, but before
definitive surgical/radiation therapy.
• Localised cancer
• Local therapies are less than completely
effective

21. Neo-adjuvant therapy
Rationale
• Immediate exposure of local and possible
distant disease to effective chemotherapy,
avoiding the delay introduced by surgery
• Immediate in vivo assessment of chemotherapy
responsiveness of the primary tumor, and
therefore, of possible nodal or distant
micrometastatic disease

22. Neo-adjuvant therapy
• Reduce the size of primary tumor
• Better chance of complete resection
• Preservation of organ function
o Laryngeal cancer
o Anal cancer
o Osteosarcoma
o Bladder cancer

23. Proven role of Neo-adjuvant
therapy
 Anal cancer  Lung cancer
 Bladder cancer  Ovarian cancer
 Breast cancer  Osteosarcoma
 Cervical cancer  Rectal cancer
 Head and neck Soft tissue
cancer sarcoma

24. Cytokinetics

25. • ‘kinetics’:- Changes in magnitude over time.
Size, shape, velocity etc.
• Changes at cellular levels---- cytokinetics
• Correlation between cytokinetics and clinical
behaviour
Cell proliferation is associated with
generation of tumor heterogeneity

26. Growth Curve Analysis
• Mathematical model
• Describes the Increase or Decrease of cells
• Summarises the clinical course, emergence
of mutations
• Growth curves proved useful in new
therapeutic approaches

28. Growth Curve Analysis
30 doublings = 1 billion cells=1 cm3 mass
will take approximately 5 years.
Tumor with 109 is often curable
Tumor with 1012 is usually fatal

29. Skipper-Wilcox model
• The log-kill model
• Hypothesised the exponential growth kinetics
• Based on murine leukemia cells L1210
• Constant doubling time
Eg:-
12 hours for 100 cells to grow to 200 cells
12 hours for 109 cells to grow to 2 X 109 cells

30. Skipper model
• Cell kill is proportional, regardless of
tumor burden
• Cardinal rule of Chemotherapy
• Invariable inverse relation between cell
number and curability was established
with Skipper model

31. Clinical relevance of exponential
growth
 Cancers with <1 month doubling time
• Testicular cancers and Choriocarcinoma
- More responsive to therapy
 Cancers with 2 months doubling time
• Squamous cell cancers of Head and Neck
- Less responsive to chemo
 Cancers with more than 3 months doubling time
• Adenocarcinoma colon
- Unresponsive

32. Faster growth
• Tumor with shorter doubling time
• Means higher fraction of dividing cells
• More responsive to chemo that kills dividing
cells

33. Slower growth
 Slow growth due to :-
 less number of dividing cells
- Impede response to drugs that kill
only dividing cells
 more cell loss from apoptosis
- Higher rate of mutations
- Impede response to drugs due to
resistance

34. Skipper-Wilcox model in
combination chemotherapy
• One log kill= reduction in cell numbers from
106 cells to 105 cells and so on.
• One log kill will kill 90% population of tumor
cells

35. Fundametal concepts of
combination therapy
• Drug A has one log-kill. (90% cells eliminated, 10%
remaining)
• If drug B, also with one log-kill is given next,
• Then it will kill 90% of the remaining 10%, making the
total to 99% tumor cells eliminated 99% =2 log-kill.
• To achieve 2 log kill with drug A alone or drug B
alone we need to double the dose of A or B.
• This means more cytotoxicity.

36. • One log kill with A + one log kill with B has achieved
2 log kill
• There was no increased cytotoxicity with the
combination.
• A+B+C (each with one log kill) will reduce tumor
size from 106 cells to 103 cells to 100 cells
• Thereby eradicating the tumor.

37. • Clinical trials could not replicate this optimistic
predictions. (adjuvant therapy for
micrometastasis in breast cancer)
• Divergence from the model may be due to drug
resistance

38. Delbruck-Lubria model
• Model to explain the emergence of drug
resistance.
- Bacterial culture based
• Percentage of cells that randomly acquired
denovo resistance of bacteriophage.

39. Delbruck-Lubria Hypothesis
• More mitosis means more chance of
acquiring a resistant mutations
• More mitosis also means aberrant DNA and
tumor heterogeneity

40. Goldie-Coldman model
• Delbruck model was re-applied to human
cancer

41. Goldie-Coldman model
• When the tumor increase in size by 2 log(100 times),
then the possibility of drug resistant mutations is very
high
• When the tumor increases in size, the metastatic
ability also increases
• Ca breast
 T= <1 cm, only 17 % axillary mets
 T=2 cm, 41% axillary mets
 T=5-10 cm, 68% axillary mets

42. Goldie-Coldman model
• A tumor has 90% chance of cure at a size of 105 cells
and certainly incurable by 107 cells.
• Means, tumor larger than 1 cm3 (at a packing ratio of
1:100) will always be incurable with single agent.
• Best strategy is to treat a small tumor as early as
possible

43. Evidence to the contrary
• Gestational choriocarcinoma and Burkitt's lymphoma
• Rapidly growing cancers
• Cured with single drugs
• Childhood ALL and GCT of 1010 cells were cured with
2 agent combination.
• Hence, a size of 107 cells , does not always mean
incurability

44. Goldie-Coldman model
• As many effective drugs to be used as soon as possible
(Combination chemotherapy).
• If several drugs cannot be used simultaneously, then
they should be used in strict alternating regimen as
compared to sequential regiment.
• Chemotherapeutic failure in sequential regimen was
assumed due to development of absolute drug
resistance

45. Evidence to the contrary
• Breast cancer that regrow after exposure to
adjuvant CMF are NOT universally resistant
to CMF
• A Temporary absolute drug resistance that
reverses over time explains this clinical
phenomena

46. Goldie-Coldman model
• Alternating chemotherapy is better than
Sequential chemotherapy.
- AB AB AB better than AAA BBB

47. Evidence to the contrary
• ProMACE-MOPP hybrid was not better than
ProMACE full course followed by MOPP in NHL.
• No advantage of CMFVP alternating with VATH
over CAF or VATH alone in Ca Breast.
• Sequential application of intensive induction
followed by intensive consolidation was better in
leukemia

48. Goldie-Coldman model
• Applicable to some aspects of cancer biology.
• Several of model predictions were not
sustained by clinical data.

49. Patterns of Growth
• Exponential pattern of growth :-
• 1,2,4,8,16.... and so on in equal units of time
• Linear pattern of growth :-
• 1, 2, 3, 4,.... and so on in equal units of time

50. Linear growth 1,2,3,4…..
• 2 years to grow from 1 cell to 1010 cells (10 cm3)
• Another 2 years to double its size (20 cm3)
• Another 2 years to triple its size (30 cm3)
• Unrealistically slow growth for an untreated primary
cancer
• So ??????? linear growth

51. Exponential growth
• 2 years to grow from 1 cell to 1010 cells (10 cm3)
• Mass will double its size in every 22 days
• Reach a size of 40 cm3 in less than 7 weeks from
diagnosis.
• Incompatible with clinical experience
• So ????????????? exponential growth

52. Gompertzian growth
• Growth of tumor is EXPONENTIAL to start with and
deviates towards LINEAR, as the tumor becomes
larger.
• This is called DECREMENTAL EXPONENTIAL
growth curve.

53. Gompertzian model
• In exponential growth model, the doubling
time is fixed.
• In Gompertzian growth, doubling time
increases as the tumor grows larger.
• Growth fraction peaks when tumor is approx.
37% of its max size

54. Gompertzian model
Advanced tumor
large tumor mass
low growth fraction
fractional cell kill is small.
• Response to chemo depends on WHERE the
tumor is, in its growth phase

55. Gompertzian model
• Predictions about behaviour of tumors.
• Clinically undetectable tumor- high growth
fraction.
• Fractional cell kill high with the effective dose
of chemo agent.

56. Norton-Simon model
•Surviving fraction of a tumor after chemotherapy
is inversely related to the tumor size at the start
of treatment.
•Tumor regression is greater when tumor size is
bigger at the start of treatment

57. Gompertzian model

58. Principles of Dose, Schedule
and Combination Therapy

59. Relation between
Dose and Effect
Log cell kill be greater with :-
Greater dose intensity - dose intensity.
 INC. total amount of drug
received
- DOSE ESCALATION
 Amount of drug received per unit time
- DOSE DENSITY
-The third approach involves sequential scheduling
of either single agents, which is, in effect,
combination chemotherapy in sequence

60. Dose Intensity
Dose escalation :-
• Achieved by raising the dose level
Dose density :-
• Achieved by shortening the duration
of treatment

61. Dose Intensity
• Regimen 1
X mg over Y days
• Regimen 2
2X mg over Y days  DOSE ESCALATION
• Regimen 3
X mg over Y/2 days  DOSE DENSITY
• Both regimen 2 and 3 are more dose intensive than
regimen 1.

62. Dose Intensity
• Regimen 2 ( 2X mg over Y days)
• Regimen 3 (X mg over Y/2 days)
• Dose Intensity of drug delivery in regimen 2= 2X/Y
• Dose Intensity of regimen 3= X/ Y/2=2X/Y
• But regimen 2 delivers more total drug (2X) than
regimen 3 (X), and hence is superior.

63. • Regimen 2 is more EFFECTIVE than
regimen 3 though both have the same d
ose intensity.
• But, it is NOT feasible due to life
threatening toxicities involved.
• Hence, the next best method to
increase the intensity is by increasing
the density.

64. Dose density
A landmark randomized phase 3 trial
Comparing dose-dense versus conventionally scheduled
chemotherapy in the adjuvant treatment of node-positive
primary breast cancer (INT C9741).
In this study, Citron et al.21 showed that a dose-dense
schedule in which the anticancer agents doxorubicin,
cyclophosphamide, and paclitaxel were administered
every 2 weeks rather than at the conventional
3-week intervals.
Resulted in significantly improved clinical outcomes with
respect to disease-free survival and overall survival.

65. Contd
Egs of dose dense regimens
metastatic colorectal cancer, extensive-stage
small-cell lung cancer, and poor-prognosis
germ cancer.

66. Dose density-Sequencial Rx
Limitation of modern combination chemotherapy -- dose
levels of individual drugs are reduced in an effort to limit
toxicity when the drugs are used in combination.
A randomized clinical trial by Bonadonna and Zambetti four
3-week cycles of doxorubicin followed by eight 3-week
cycles of CMF
In high-risk primary breast cancer (four or more positive
lymph nodes).
Results:Improved clinical efficacy in terms of disease-free
and overall survival in seq than in alternating schedule of
doxorubicin and CMF at the same dose intensity.

67. Contd
Sledge et al.- sequential versus combination therapy in the Eastern
Cooperative Oncology Group E1193 randomized phase 3 Trial
Combination CT in sequence, with doxorubicin and paclitaxel
versus
a combination of the two agents as the first-line treatment
( metastatic breast cancer)
Results:
Combination therapy yielded a superior response rate and time to
disease progression but has not yet translated into a survival benefit
when compared with sequential single-agent therapy. Such
sequential strategies are being tested for treatment of other solid
tumors, including colorectal cancer and ovarian cancer.

68. Summation Dose Intensity
• Relation between Dose intensity and
Combination Chemotherapy.
• Efficacy of a combination is related to sum
of dose intensities of all the agents used.

69. Single agent - Choriocarcinoma ,Burkit’s lymphoma
Combination chemotherapy
Advantages
1. Maximal cell kill within the range of toxicity tolerated by
the host for each drug.
2. It provides a broader range of interaction between drugs
and tumor cells with different genetic abnormalities in a
heterogeneous tumor population.
3. It may prevent and/or slow the subsequent development
of cellular drug resistance.

71. THANK U…