Jim Burch, MS, PhD, Jim Burch, MS, PhD, Assistant ProfessorAssistant Professor

Department of Epidemiology and BiostatisticsDepartment of Epidemiology and BiostatisticsCancer Prevention and Control ProgramCancer Prevention and Control ProgramCenter for Colorectal Cancer ResearchCenter for Colorectal Cancer Research

University of South Carolina University of South Carolina Dorn VA Medical CenterDorn VA Medical Center

Columbia, SCColumbia, SC

E-mail: burch@gwm.sc.edu Phone: 803 734-4459

Circadian Disruption & CancerCircadian Disruption & Cancer

ObjectivesObjectives

Provide an overview of human circadian systems Provide an overview of human circadian systems Summarize the effects of shift work on circadian systemssSummarize the effects of shift work on circadian systemss Describe how circadian biology relates to carcinogenesisDescribe how circadian biology relates to carcinogenesis

“Timing is everything...”

The Endogenous ClockThe Endogenous Clock

• SCN neurons have an endogenous rhythm

• Ambient light sets/resets the SCN, providing Ambient light sets/resets the SCN, providing timing cues to peripheral oscillators timing cues to peripheral oscillators (heart, liver, kidneys)(heart, liver, kidneys)

• Timing cues are neural or hormonalTiming cues are neural or hormonal

• In response to these signals, the organism In response to these signals, the organism displays circadian (~24-hour) rhythms in displays circadian (~24-hour) rhythms in physiology & behaviorphysiology & behavior

• Cellular metabolism & proliferation also Cellular metabolism & proliferation also show circadian coordination w/in tissuesshow circadian coordination w/in tissues

Canaple, L. et al. Cancer Res 2003;63:7545-7552

• Bmal1 & ClockBmal1 & Clock expressed in ~24-hour cycles expressed in ~24-hour cycles

• Form a heterodimer that regulates other clock gene Form a heterodimer that regulates other clock gene expression, maintains endogenous circadian rhythmsexpression, maintains endogenous circadian rhythms

• PeriodPeriod ( (perper) and ) and CryptochromeCryptochrome ( (CryCry) genes are ) genes are transcribed & translated in response to Bmal1 & transcribed & translated in response to Bmal1 & ClockClock

• Per & Cry form a negative feedback loop by Per & Cry form a negative feedback loop by inhibiting Bmal1 & Clock transcriptional activation, inhibiting Bmal1 & Clock transcriptional activation, thus lowering their own expressionthus lowering their own expression

• Per and Cry also increase Bmal1 & Clock gene Per and Cry also increase Bmal1 & Clock gene transcription, initiating next phase of the cycletranscription, initiating next phase of the cycle

• This cycle runs autonomously in the cell, but can be This cycle runs autonomously in the cell, but can be regulated (entrained) by ambient lightregulated (entrained) by ambient light

• Casein kinase 1 epsilonCasein kinase 1 epsilon (CK1e) phosphorylates (CK1e) phosphorylates Per2 & induces degradationPer2 & induces degradation

Source: www.biocarta.com/pathfiles/ h_circadianPathway.asp

Clock Genes: Molecular Basis of Circadian RhythmsClock Genes: Molecular Basis of Circadian Rhythms

Clock Gene Disregulation & CancerClock Gene Disregulation & Cancer

Clock genes help regulate cell cycle timing, DNA synthesis & Clock genes help regulate cell cycle timing, DNA synthesis & repair, apoptosis (SCN & peripheral issues)repair, apoptosis (SCN & peripheral issues)

Source: Canaple, L. et al. Cancer Res. 63:7545-52. 2003Source: Canaple, L. et al. Cancer Res. 63:7545-52. 2003

Common elements shared by biological clocks & the cell cycle

Melatonin & Circadian RhythmsMelatonin & Circadian Rhythms

United States at NightKusanagi et al. Neurosci Lett. 365:124–7. 2004

Adapted from: Wilson BW. Biol. Effects of EMFs Vol. I. Academic Press, NY. 1994.

The Melatonin HypothesisThe Melatonin Hypothesis

Shift Work & Circadian DesynchronizationShift Work & Circadian Desynchronization

20% of U.S. work force performs shift 20% of U.S. work force performs shift work (~15 MM); ~20-30% attrition rate work (~15 MM); ~20-30% attrition rate w/in 2-3 yearsw/in 2-3 years

Critical work sectorsCritical work sectors: medical care : medical care providers, emergency response teams providers, emergency response teams (police, fire, rescue), military personnel, (police, fire, rescue), military personnel, public utilities, transportationpublic utilities, transportation

Shift workers suffer fromShift workers suffer from: chronic: chronicfatigue, sleep disorders, increasedfatigue, sleep disorders, increasedaccident & injury rates, deceasedaccident & injury rates, deceasedproductivity (approx. $55 BB/year)productivity (approx. $55 BB/year)

Health effectsHealth effects: gastrointestinal &: gastrointestinal & reproductive disorders, cardiovascularreproductive disorders, cardiovascular

disease, cancerdisease, cancer

Personal MonitoringPersonal Monitoring: : Rest/activity & urine samples,Rest/activity & urine samples, 24-hr period, 3rd day of work week24-hr period, 3rd day of work week

SymptomsSymptoms: Questions regarding sleep disturbances, fatigue,: Questions regarding sleep disturbances, fatigue, mental state from mental state from Standard Shift Work IndexStandard Shift Work Index

Sleep AnalysisSleep Analysis: Total sleep time, sleep efficiency sleep latency, : Total sleep time, sleep efficiency sleep latency, sleep fragmentation, ambient light exposure via wrist actigraphysleep fragmentation, ambient light exposure via wrist actigraphy

BiomarkersBiomarkers:: Post-Work and Post-Sleep urinary Post-Work and Post-Sleep urinary melatoninmelatonin metabolitemetabolite (6-OHMS) levels; cr-adjusted & total sleep time (6-OHMS) levels; cr-adjusted & total sleep time excretion; 73 questionnaire items screenedexcretion; 73 questionnaire items screened

Circadian DesynchronizationCircadian Desynchronization: Sleep: Sleep::Work 6-OHMS RatioWork 6-OHMS Ratio Note: if ratio Note: if ratio << 1 => disrupted melatonin rhythm1 => disrupted melatonin rhythm

Melatonin, Sleep, & Shift Work AdaptationMelatonin, Sleep, & Shift Work Adaptation(Burch et al. J Occ Environ Med. 47:893-901. 2005)(Burch et al. J Occ Environ Med. 47:893-901. 2005)

PopulationPopulation DemographicsDemographicsFactorFactor RF WorkersRF Workers ComparisonComparison

N 53 112Mean Age 36 ± 11 34 ± 11Female 32 (60%) 75 (67%) Education > High School 23 (44%) 43 (39%)Ethnicity White, Non-Hispanic 17 (32%) 48 (43%) Hispanic 10 (19%) 36 (32%) Asian, Pacific Islander 20 (38%) 18 (16%) Other (Black or Native American) 6 (11%) 9 ( 8%)Work Duration (years) 2.8 ± 3.9 3.2 ± 4.7Shift Work Day (6:00 am - 2:00 pm) 25 (47%) 46 (41%) Swing (2:00 pm - 10:00 pm) 28 (53%) 34 (30%) Night (10:00 pm - 6:00 am) 0 32 (29%)

FactorFactor RF WorkersRF Workers ComparisonComparison

N 53 112Mean Age 36 ± 11 34 ± 11Female 32 (60%) 75 (67%) Education > High School 23 (44%) 43 (39%)Ethnicity White, Non-Hispanic 17 (32%) 48 (43%) Hispanic 10 (19%) 36 (32%) Asian, Pacific Islander 20 (38%) 18 (16%) Other (Black or Native American) 6 (11%) 9 ( 8%)Work Duration (years) 2.8 ± 3.9 3.2 ± 4.7Shift Work Day (6:00 am - 2:00 pm) 25 (47%) 46 (41%) Swing (2:00 pm - 10:00 pm) 28 (53%) 34 (30%) Night (10:00 pm - 6:00 am) 0 32 (29%)

Melatonin Metabolite Levels among Shift WorkersMelatonin Metabolite Levels among Shift Workers

LS means adjusted for: month, gender, smoking, alcohol consumption; 1vs.2 p=0.53; 1 vs. 3 p=0.08

0

1

2

3

4

5

6

7

8

9

1 2 3Work Shift

Tot

al S

leep

-tim

e 6-

OH

MS

(µ

g)

n=71n=71 n=62n=62 n=32n=32

Melatonin Metabolite Levels among Shift WorkersMelatonin Metabolite Levels among Shift Workers

0

2

4

6

8

10

12

14

16

1 2 3Work Shift

Mea

n 6-

OH

MS

(ng/

mg

cr)

Post-Sleep

Post-Work

LS means adjusted for: month, second-hand smoke, concern, eye color, BMI, alcohol (P-S); and month, gender (P-W)

Melatonin Metabolite Ratios among Shift WorkersMelatonin Metabolite Ratios among Shift Workers

0

1

2

3

4

5

6

1 2 3Work Shift

Sle

ep:W

ork

6-O

HM

S R

atio

* p = 0.02 vs. Shift 1

*

Adjusted for: gender, missed work, tetrahydrofuran exposure. Source: Burch et al., JOEM 47:893-901. 2005.

n=71n=71 n=62n=62 n=32n=32

Sleep Characteristics among Shift WorkersSleep Characteristics among Shift Workers

Burch et al. J Occ Environ Med. 47:893-901. 2005Burch et al. J Occ Environ Med. 47:893-901. 2005

Distribution of Symptoms among Shift WorkersDistribution of Symptoms among Shift WorkersAny Symptom

3434 3131 202042424343 2323 18183030 77

Any Symptom

0

10

20

30

40

50

60

70

80

1 2 3

Work Shift

Sym

ptom

Fre

quen

cy (

%)

Sleep

Fatigue

Mental

(n=71) (n=62) (n=32)

Any Symptom

202031313434 4343 4242 18182323 3030 77

Sleep: insomnia, quality, not rested, wake, fall; Fatigue: energy, drained, not alert, exhausted; Mental: memory, conc, dizzy, headache

Distribution of Symptoms among Shift WorkersDistribution of Symptoms among Shift Workers2 or More Symptoms

0

10

20

30

40

50

60

1 2 3Work Shift

Sym

ptom

Fre

quen

cy (%

)

Sleep

Fatigue

Mental

88 1414 111126262828 1010 9977 44

2 or More Symptoms

Sleep: insomnia, quality, not rested, wake, fall; Fatigue: energy, drained, not alert, exhausted; Mental: memory, conc, dizzy, headache

SymptomSymptomN (%)N (%)

SLEEP:WORKSLEEP:WORK6-OHMS 6-OHMS << 1 1

(N=21) (N=21)

SLEEP:WORK SLEEP:WORK 6-OHMS > 16-OHMS > 1

(N=144) (N=144)

Odds Odds RatioRatio

95% CI95% CI(Fisher’s (Fisher’s

exact p-value)exact p-value)

Mental:Mental: NoneNone At least 1At least 1 2 or More2 or More

66 (30%) (30%)

77 (35%) (35%) 77 (35%) (35%)

9797 (67%) (67%)

32 32 (22%)(22%)

1414 (10%) (10%)

1.01.03.53.58.18.1

----

1.1 - 11.3 1.1 - 11.3 (0.04)(0.04)2.4 - 27.5 2.4 - 27.5 (<0.01)(<0.01)

Sleep:Sleep: NoneNone At least 1At least 1 2 or More2 or More

66 (43%) (43%)

55 (45%) (45%) 88 (57%) (57%)

7171 (74%) (74%)

44 44 (38%)(38%)

2525 (26%) (26%)

1.01.01.31.33.83.8

----

0.4 – 4.7 (0.4 – 4.7 (0.75)0.75)1.2 – 12.0 (1.2 – 12.0 (0.03)0.03)

Fatigue:Fatigue: NoneNone At least 1At least 1 2 or More2 or More

33 (15%) (15%)

77 (35%) (35%)1010 (50%) (50%)

5555 (41%) (41%)

27 27 (20%)(20%)

5353 (39%) (39%)

1.01.04.74.73.53.5

----

1.1 - 19.8 (1.1 - 19.8 (0.03)0.03)0.9 - 13.3 (0.9 - 13.3 (0.07)0.07)

Symptoms among Shift Workers with Symptoms among Shift Workers with Disrupted Circadian Melatonin ProductionDisrupted Circadian Melatonin Production

High Interdaily Stability (IS)High Interdaily Stability (IS)ID: 1151

0

200

400

600

800

1000

1200

9:4

7

12:1

1

14:3

6

17:0

1

19:2

6

21:5

0

0:1

5

2:4

0

5:0

5

7:2

9

9:5

4

12:1

9

14:4

4

17:0

8

19:3

3

21:5

8

0:2

3

2:4

7

5:1

2

7:3

7

10:0

2

12:2

6

14:5

1

17:1

6

19:4

1

22:0

5

0:3

0

2:5

5

5:2

0

7:4

4

10:0

9

12:3

4

time

ac

tiv

ity

ID: 1009

-50

50

150

250

350

450

550

650

750

850

15

:50

17

:51

19

:52

21

:53

23

:54

1:5

5

3:5

6

5:5

7

7:5

8

9:5

9

12

:00

14

:01

16

:02

18

:03

20

:04

22

:05

0:0

6

2:0

7

4:0

8

6:0

9

8:1

0

10

:11

12

:12

14

:13

16

:14

18

:15

20

:16

22

:17

0:1

8

2:1

9

4:2

0

time

activ

ity

ID:1182

-100

400

900

1400

12:5

4

15:1

7

17:4

0

20:0

3

22:2

7

0:5

0

3:1

3

5:3

6

8:0

0

10:2

3

12:4

6

15:0

9

17:3

3

19:5

6

22:1

9

0:4

2

3:0

6

5:2

9

7:5

2

10:1

5

12:3

9

15:0

2

17:2

5

19:4

8

22:1

2

0:3

5

2:5

8

5:2

1

7:4

5

10:0

8

12:3

1

14:5

4

17:1

8

time

acti

vit

y

ID: 1241

0

100

200

300

400

500

8:2

7

10:4

2

12:5

7

15:1

2

17:2

8

19:4

3

21:5

8

0:1

3

2:2

9

4:4

4

6:5

9

9:1

4

11:3

0

13:4

5

16:0

0

18:1

5

20:3

1

22:4

6

1:0

1

3:1

6

5:3

2

7:4

7

10:0

2

12:1

7

14:3

3

16:4

8

19:0

3

21:1

8

23:3

4

1:4

9

4:0

4

6:1

9

8:3

5

10:5

0

time

acti

vit

y

Low Interdaily Stability (IS)

High Relative Amplitude (RA)ID:1071

0

200

400

600

800

1000

1200

12:4

1

14:5

4

17:0

8

19:2

2

21:3

6

23:4

9

2:0

3

4:1

7

6:3

1

8:4

4

10:5

8

13:1

2

15:2

6

17:3

9

19:5

3

22:0

7

0:2

1

2:3

4

4:4

8

7:0

2

9:1

6

11:2

9

13:4

3

15:5

7

18:1

1

20:2

4

22:3

8

0:5

2

3:0

6

5:1

9

7:3

3

9:4

7

time

acti

vit

y

ID:1094

0100200300400500600700800

10:3

9

12:4

4

14:5

0

16:5

6

19:0

2

21:0

7

23:1

3

1:1

9

3:2

5

5:3

0

7:3

6

9:4

2

11:4

8

13:5

3

15:5

9

18:0

5

20:1

1

22:1

6

0:2

2

2:2

8

4:3

4

6:3

9

8:4

5

10:5

1

12:5

7

15:0

2

17:0

8

19:1

4

21:2

0

23:2

5

1:3

1

3:3

7

5:4

3

7:4

8

9:5

4

12:0

0

time

acti

vit

y

ID:1256

0

500

1000

1500

2000

11:3

6

13:5

0

16:0

5

18:2

0

20:3

5

22:4

9

1:04

3:19

5:34

7:48

10:0

3

12:1

8

14:3

3

16:4

7

19:0

2

21:1

7

23:3

2

1:46

4:01

6:16

8:31

10:4

5

13:0

0

15:1

5

17:3

0

19:4

4

21:5

9

0:14

2:29

4:43

6:58

9:13

11:2

8

13:4

2

time

acti

vity

ID:1187

-100

100

300

500

700

9:31

11:5

4

14:1

8

16:4

1

19:0

5

21:2

8

23:5

2

2:15

4:39

7:02

9:26

11:4

9

14:1

3

16:3

6

19:0

0

21:2

3

23:4

7

2:10

4:34

6:57

9:21

11:4

4

14:0

8

16:3

1

18:5

5

21:1

8

23:4

2

2:05

4:29

6:52

9:16

11:3

9

14:0

3

timeac

tivi

ty

Low Relative Amplitude (RA)

Characterizing Circadian Rest/Activity Rythms

Melatonin & Circadian Rest/Activity Rythms

Shift Work & Melatonin: SummaryShift Work & Melatonin: Summary

Workers on permanent night shifts had a disrupted Workers on permanent night shifts had a disrupted 24-hour melatonin rhythm24-hour melatonin rhythm

Desynchronized circadian melatonin rhythm associated Desynchronized circadian melatonin rhythm associated with sleep disruption, fatigue, and mental symptiomswith sleep disruption, fatigue, and mental symptioms

Disrupted melatonin rhythms may be associated withDisrupted melatonin rhythms may be associated with poor performance and increased accident/injury riskpoor performance and increased accident/injury risk

Disrupted circadian rest/activity rhythms associated withDisrupted circadian rest/activity rhythms associated with low melatoninlow melatonin

Methods implemented in this study can be applied toMethods implemented in this study can be applied to health studies (shift workers, cancer patients)health studies (shift workers, cancer patients)

Shift Work & Cancer RiskShift Work & Cancer RiskOccupations linked with Occupations linked with breast cancerbreast cancer

risk include: Flight Attendants, Nursing risk include: Flight Attendants, Nursing & Health Care& Health Care

Recent more carefully controlled studies Recent more carefully controlled studies support previous results support previous results (e.g., Nurses Health Study cohort)(e.g., Nurses Health Study cohort)

More recent studies link shift work w/ More recent studies link shift work w/ colorectalcolorectal & & prostateprostate cancer risks cancer risks

Shift (night) workers have altered Shift (night) workers have altered neuroendocrine function, disturbed sleep, neuroendocrine function, disturbed sleep, increased stress. increased stress.

Biological mechanism to explain cancer Biological mechanism to explain cancer risk is not fully understood?risk is not fully understood?

Sleep Disruption

Circadian RhythmDisruption

Fatigue

Depression

Chronic StressChronic Stress

CANCER

↓↓ MelatoninMelatonin ~ Clock Proteins~ Clock Proteins ~ Cortisol~ Cortisol ↑↑CytokinesCytokines

Social Social FactorsFactors

StressStressIndividualIndividual

FactorsFactorsCircadianCircadian

FactorsFactors

Source: Antoni MH, et al. Nat Rev Cancer. 2006 Mar;6(3):240-8

Stress & Cancer

• Many inflammatory diseases linked with stress • Local stress effects may be pro-inflammatory• Stress, negative emotions associated w/ pro-neoplastic cytokines: IL-1, TNF-alpha, gamma interferon, IL-6, VEGF

Source: Sephton et al. JNCI. 92:994-1000. 2000.

Disrupted Cortisol Rhythm & Breast Cancer SurvivalBreast Cancer Survival

Rich et al. Clin Cancer Res. 11:1757-64. 2005. Mormont et al. Clin Cancer Res. 6: 3038-45. 2000

Right. Kaplan-Meier estimates of survival as a function of the 24-h rhythm parameters, r24 (a) and I<O (b), assigned to quartiles: 1 - very high; 2 -high; 3 - low; 4 - very low. Survival curves compared with log-rank test (r24 p=10-4; I<O p=10-4). Left. Cytokine serum levels for TNF-a, TGF-a, and IL-6 in patientswith ‘‘good’’ (>0.47) or ‘‘dampened’’ (<0.35) activity rhythm measured by the autocorrelation coefficient r24.

Circadian Disruption

& Metastatic Colorectal

Cancer

Inhibits breast cancer cell Inhibits breast cancer cell growth growth in vitro in vitro (MCF-7) (MCF-7)

Modulates estrogen Modulates estrogen receptor signaling receptor signaling

Suppresses reproductive Suppresses reproductive hormone (estrogen) hormone (estrogen) secretionsecretion

Stimulates the immune Stimulates the immune system (T, NK cells)system (T, NK cells)

Inhibits breast cancer cell Inhibits breast cancer cell growth growth in vitro in vitro (MCF-7) (MCF-7)

Modulates estrogen Modulates estrogen receptor signaling receptor signaling

Suppresses reproductive Suppresses reproductive hormone (estrogen) hormone (estrogen) secretionsecretion

Stimulates the immune Stimulates the immune system (T, NK cells)system (T, NK cells)

Melatonin & Breast CancerMelatonin & Breast Cancer

Inhibits chemically induced mammary tumors Inhibits chemically induced mammary tumors in vivoin vivo Melatonin concentrates human breast tumors; levels decrease with Melatonin concentrates human breast tumors; levels decrease with increasing tumor size, stage & gradeincreasing tumor size, stage & grade Reduced nocturnal production linked with increased breast cancer risks, Reduced nocturnal production linked with increased breast cancer risks, clinical trials underwayclinical trials underway

Melatonin & Colon CancerMelatonin & Colon Cancer Melatonin & its receptors Melatonin & its receptors

are present in human colon are present in human colon and GI tissueand GI tissue

MelatoninMelatonin exerts exerts antiproliferative effects on antiproliferative effects on normal colonic epithelial as normal colonic epithelial as well as colon cancer cells well as colon cancer cells in in vitrovitro

Melatonin may have local Melatonin may have local anti-inflammatory anti-inflammatory properties (decr. COX-2)properties (decr. COX-2)

Melatonin & its receptors Melatonin & its receptors are present in human colon are present in human colon and GI tissueand GI tissue

MelatoninMelatonin exerts exerts antiproliferative effects on antiproliferative effects on normal colonic epithelial as normal colonic epithelial as well as colon cancer cells well as colon cancer cells in in vitrovitro

Melatonin may have local Melatonin may have local anti-inflammatory anti-inflammatory properties (decr. COX-2)properties (decr. COX-2)

Melatonin administration effective in animal models for treatment of colitis & Melatonin administration effective in animal models for treatment of colitis & colon cancercolon cancer Clinical trials using melatonin increase 1-yr survival (colorectal & other cancer Clinical trials using melatonin increase 1-yr survival (colorectal & other cancer patients)patients)

Circadian Tumor Circadian Tumor GrowthGrowth

Tumors exhibit Tumors exhibit rhythmic growth rhythmic growth patterns that are patterns that are in phase with in phase with clock gene clock gene expression expression (therapeutic (therapeutic application?)application?)

Clock gene Clock gene disruption (disruption (perper) ) linked with linked with circadian circadian disturbances & disturbances & increased cancer increased cancer susceptibility susceptibility

Wood et al. Mol Cancer Ther. 5:2023-33. 2006.

Phenotypic Characteristics of SNPs in Circadian Genes

CircadianPreference

Sleep Disruption

Reduced Melatonin Production

CancerRiskTarget Gene

AA-NAT Biosynthetic Enzyme √ √

Mel1a Melatonin Receptor √

Per3 Clock Gene √ √ √

Circadian Disruption Genetic Susceptibility Markers Circadian Disruption Genetic Susceptibility Markers Single Nucleotide Polymorphisms (SNPs)Single Nucleotide Polymorphisms (SNPs)

There are ~2-3 million SNPs in the human genome, some result in slightly different protein isoforms. www.bioteach.ubc.ca/Bioinformatics/DeCODE

Zhu et al. Cancer Epidemiol Biomarkers Prev. 14: 268–70. 2005.

Clock Genes & Breast CancerClock Genes & Breast Cancer

Dorn VA Hospital Colonoscopy Patients(N≈ 4,000/year; ~50% with polyps)

Case-Control Study (n=600 Men)Controls: Patients without polyps or colon cancer (n=200)Cases: Patients with colorectal polyps (n=200) or colon cancer (n=200)

Circadian Disruption Signs & Symptoms• Sleep Habits & Complaints• Fatigue, Stress • Depressive Symptoms • Circadian Type

Genetic Polymorphisms• Melatonin Genes: AA-NAT, Mel-1a, Mel-1b• Clock Gene: Per3• Others ?

Personal & Social Co-Variates• Sociodemographics • Colon Cancer & Polyp Risk Factors• Major Life Events• Social Support, Coping• Occupation, Lifestyle

Wrist Actigraphy• Rest/Activity Rhythms • Sleep Parameters

STUDY SCHEMASTUDY SCHEMA

Base PopulationBase Population

SubjectsSubjects

Outcomes

Cancer Chronotherapy

Source: Levi F. Cancer Causes & Control.17:611–621. 2006.

Role of Circadian Disruption in Polyp Formation and RecurrenceRole of Circadian Disruption in Polyp Formation and Recurrence Phase 1: Case-Control Study Phase 2: Randomized Clinical Trial

Base Population

Outcomes

Dorn VA Hospital Colonoscopy Patients(N=~4,000/yr, ~25% w/polyps)

N=300 Men (50% AA, 50% EA):Controls: Patients w/o Polyps (n=150)

Cases: Dysplastic Polyps (n=150) Subjects

Circadian Disruption Signs & Symptoms• Circadian Type, Mood, Fatigue, • Sleep Habits & Complaints, Light Levels

Genetic Polymorphisms • Melatonin Genes: AA-NAT, Mel-1a, Mel-1b• Clock Gene: Per3

Personal Monitoring • 24-Hour Rest/Activity Rhythm• Weekly Average Quantitative Sleep Parameters• Weekly Average Ambient Light Exposures

Personal & Social Co-Variates• Sociodemographics, CRC Risk Factors,

• Lifestyle, Social Support, Life Events• Work Factors, Coping Strategies

Phase 1 Men with:Mild, Moderate, or Severe Polyps

Randomization • Placebo• Evening Melatonin (2 mg/day)

Baseline• Night:Day Melatonin Metabolite Ratio

• 24-Hour Body Temperature Rhythm

• Fatigue• Depression/Anxiety

Post-Treatment• Night:Day Melatonin Metabolite Ratio

• 24-Hour Body Temperature Rhythm

• Fatigue• Depression/Anxiety• Polyp Recurrence (Rate & Severity)

9 MonthTreatment

Continuous Personal Monitoring (Actigraphy):• 24-Hour Rest/Activity Rhythms• Weekly Average Quantitative Sleep Parameters• Weekly Average Ambient Light Exposures

Stress Associated Diseases & ConditionsStress Associated Diseases & Conditions Cardiovascular

• Coronary artery disease• Hypertension• Stroke• Arrhythmias

Musculoskeletal• Tension Headaches• Muscle contraction backache

Connective Tissue• Rheumatoid arthritis• Eczema• Neurodermatitis• Acne

Pulmonary • Asthma• Allergy (hay fever)

Immune• Immunosuppression• Autoimmunity

Gastrointestinal

• Ulcer• Ulcerative colitis• Irritable bowel syndrome• Diarrhea• Nausea, vomiting

Genitourinary• Diuresis• Impotence

Endocrine • Diabetes mellitus Type 2• Amenorrhea

Central Nervous System• Depression• Fatigue, Insomnia• Overeating• Type A behavior

Salivary

cortisol levels of 104 patients with

metastatic breast cancer were assessed

at study entry at 0800, 1200, 1700, and

2100 hours on each of 3 consecutive

days, and the slope of diurnal cortisol

variation was calculated using a regression

of log-transformed cortisol concentrations

on sample collection time.

NK cell numbers were measured by

flow cytometry, and NK cell activity

was measured by the chromium release

assay. The survival analysis was conducted

by the Cox proportional hazards

regression model with two-sided

statistical testing. Results: Cortisol

slope predicted subsequent survival up

to 7 years later. Source: Sephton et al. JNCI. 92:994-1000. 2000.

Interdaily Stability (IS) and Relative Amplitude (RA)

• Both are nonparametric variables dedicated for actigraphy analyses.

• The IS, which is the strength of coupling of the rhythm to supposedly stable environmental zeitgebers, quantifies the invariability between the days. The IS is the 24h value from the chi-square periodogram, normalized for the number of data.

• The RA, a measure to describe the signal-to-noise ratio, is an alternative to the cosinor amplitude. The RA can be calculated from the most active 10h period and the least active 5h period in the average 24h pattern.

AcknowledgmentsAcknowledgments

SupportSupport: Veteran’s Administration Research Career Development Award: Veteran’s Administration Research Career Development Award

William Hrushesky, MD William Hrushesky, MD WJB Dorn VA Medical Center, COBREWJB Dorn VA Medical Center, COBRE Patricia Wood, MD, PhDPatricia Wood, MD, PhD WJB Dorn VA Medical Center, COBREWJB Dorn VA Medical Center, COBRE Wael Youssef, MDWael Youssef, MD WJB Dorn VA Medical CenterWJB Dorn VA Medical Center

James Hebert, MSPH, ScDJames Hebert, MSPH, ScD USC Dept Epidemiology & USC Dept Epidemiology & Biostatistics,Biostatistics,

COBRECOBRE Frank Berger, PhDFrank Berger, PhD USC Center for Colon Cancer ResearchUSC Center for Colon Cancer Research Shawn Youngstedt, PhDShawn Youngstedt, PhD USC Department of Exercise Science USC Department of Exercise Science Dawen Xie, MD, PhDDawen Xie, MD, PhD USC Dept Epidemiology & Biostatistics, USC Dept Epidemiology & Biostatistics,

South Carolina Cancer Center South Carolina Cancer Center Kisito Ogoussan, MS, MDKisito Ogoussan, MS, MD USC Dept Epidemiology & BiostatisticsUSC Dept Epidemiology & Biostatistics