An analysis of provincial data shows cancer in patients from poorer parts of Hamilton is more advanced by the time the disease is detected. The findings raise questions about access to health care, patient education, screening programs and the gap between rich and poor.

Patients in the former City of Hamilton are being diagnosed with later-stage cancers at disproportionately high rates compared with patients in the five suburbs of Stoney Creek, Ancaster, Dundas, Flamborough and Glanbrook.

The disturbing findings are based on four years of data provided exclusively to The Spectator by Cancer Care Ontario.

Of the city's 95 neighbourhoods that were included in the data, there are 16 where the proportion of late-stage cancer diagnoses was 40 per cent or higher for the years 2010 through 2013.

All 16 of the neighbourhoods are in the former City of Hamilton and 13 of the 16 are in the lower city.

There are seven neighbourhoods where the proportion of late-stage cancer diagnoses — those discovered in either Stage III or IV — is at least 50 per cent or higher and all seven neighbourhoods are between Queen Street and Ottawa Street in the lower city, where incomes are lower and rates of poverty are substantially higher than in the city's suburbs.

When it comes to just Stage IV cancer diagnoses — when the disease has spread to another organ and survival is generally poor — there are 13 neighbourhoods in the city where the rate is 25 per cent or higher.

All 13 of the neighbourhoods are in the former City of Hamilton and 12 of the 13 are in the lower city.

The results suggest a possible connection between the stage of cancer at diagnosis and social and economic factors, such as income, poverty levels and education.

Surviving cancer is strongly linked to the stage of the disease when it's diagnosed.

For example, when colorectal cancer is diagnosed at Stage I, the five-year survival rate is 93 per cent, according to the American Cancer Society.

But for Stage IV colorectal cancer, the five-year survival rate is less than 10 per cent.

"Whether it's cancer incidence or death or whether it's stage at presentation, it all highlights the association of socioeconomic status and illness," said Dr. Peter Ellis, a lung cancer specialist at Hamilton's Juravinski Cancer Centre.

"And it's complicated because some of the things that promote cancer — either incidence or progression — are associated with education and socioeconomic status," he added.

One way to analyze the distribution of late-stage cancer diagnoses is to look at their proportions based on population.

When looking just at Stage IV cancers, the deadliest diagnosis, The Spectator's data analysis shows that the lower part of the former City of Hamilton had 20 per cent more diagnoses than would be expected based on population.

Meanwhile, the five suburbs of Stoney Creek, Ancaster, Dundas, Flamborough and Glanbrook had about 12 per cent fewer Stage IV cancers than would be expected based on population.

In the corridor from Queen Street to Ottawa Street between the escarpment and Cannon Street, there were 28 per cent more diagnoses of Stage IV cancers than would be expected based on population. About one of every seven Stage IV cancer diagnoses occurred in this small sliver of the city.

In Flamborough, there were 61 per cent fewer Stage IV cancer diagnoses than would be expected based on population. In Ancaster, there were 22 per cent fewer Stage IV cancers than expected, based on population.

"We know in general that people who come from lower socioeconomic backgrounds have delayed access to health care," said Ellis. "These people tend to delay seeing a doctor, they don't necessarily understand some of the symptoms they see, they may be less inclined to undertake screening behaviour.

"If you don't necessarily have access to a family doctor, if your way of dealing with problems is to present to the emergency department or some sort of urgent care — which certainly happens more in those lower socioeconomic areas — then you're not going to get the continuity of care.

"The emergency department might be a good place to go if you're having a heart attack," Ellis added, "but it's not a good place to go for management of your blood pressure or of your chronic health conditions because they're geared toward just dealing with the most immediate issue in front of them."

Part of the reason for the higher rates of late-stage cancer in the lower city is due to the types of cancers involved.

Lung cancer is a particular scourge in central Hamilton.

Smoking rates are tied to income — lower-income people smoke more than higher-income people, and smoking rates are much higher in the inner city, where poverty rates are highest.

Just how big is the difference in smoking behaviours across the city?

Massive, according to an extensive Spectator survey of households conducted two years ago.

In the L8L postal codes — covering the urban core between James and Ottawa streets from Main Street to the waterfront — nearly 45 per cent of households had at least one smoker in the home.

In Ancaster's L9K postal codes, just 11 per cent of households reported at least one smoker in the home.

With increased rates of smoking come much higher rates of lung cancer in the inner city.

The incidence of lung cancer in the lower part of the former City of Hamilton was about 80 per cent higher than it was in the combined five suburbs of Stoney Creek, Ancaster, Dundas, Flamborough and Glanbrook, based on findings in The Spectator's 2013 Code Red cancer series.

Because there are no real effective early screening tools for lung cancer, the disease is notorious for being detected at a late stage.

About half of the province's lung cancer patients have already reached Stage IV — the final stage when the disease has already spread elsewhere — by the time they're diagnosed.

Another 30 per cent are diagnosed at Stage III, meaning the disease is locally advanced. Just 20 to 25 per cent are diagnosed in Stages I and II, when surgery is a realistic option.

Compare that to breast cancer, where 80 to 85 per cent of patients are diagnosed in the first two stages.

The numbers help explain why the overall five-year survival rate for lung cancer remains discouraging at just 18 per cent in Ontario. Yet when the disease is caught in Stage I or II, the survival rate jumps as high as 70 per cent.

To see how all of those factors intersect right down to the neighbourhood level, consider the chunk of Hamilton along the waterfront between Wellington Street and Sherman Avenue north of Barton Street.

Between 2000 and 2009, the rate of lung cancer cases in that neighbourhood for people 45 and older was three times higher than the Canadian average, based on CCO data provided to The Spectator.

That neighbourhood has the second-highest rate of late-stage cancer diagnoses out of nearly 100 Hamilton neighbourhoods. More than 71 per cent of cancers diagnosed in that neighbourhood between 2010 and 2013 were either Stage III or IV.

Now look at the social and economic profile of that neighbourhood. It's among the bottom 10 for the entire city in the following categories: median income for adults, adult poverty, child poverty, high-school dropouts, adults with no post-secondary education and average value of a dwelling.

"I don't think lung cancer explains the whole story," Ellis said.

"Diet, exercise, obesity, smoking — all of those contribute to cancer incidence. So you're going to see higher cancer incidence where all those things come together," he added.

Part of the reason for the higher rates of late-stage cancer in the lower city is due to lower rates of screening as well. An effective screening program can help catch cancers at earlier stages.

When it comes to breast, cervical and colorectal cancer, people in Hamilton's poorer inner-city neighbourhoods are being screened at much lower rates than people in the richer suburbs of Ancaster, Flamborough, Dundas, Glanbrook and Stoney Creek.

In some cases, the screening rates are nearly three times greater in the wealthiest neighbourhoods compared to the poorest ones.

Take breast cancer screening, for example.

The rates in Hamilton varied from a low of about 29 per cent of eligible women being screened in the inner-city's Beasley neighbourhood to more than 70 per cent of women screened in parts of Ancaster, Dundas and Glanbrook.

Better education and awareness programs could help, Ellis said, along with increased development of electronic medical databases, which could be programmed to include screening reminders.

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But those initiatives still depend on patients accessing a health-care provider in the first place.

"If education alone was the answer, then we already would have solved the problem," Ellis said, "because there's been a lot of education to try to promote awareness about health issues."

Part one Arming ourselves against cancer

Part two Cancer's costly conundrum

Park three Latest advances in treatment

Part four Hamilton's top researchers

Part five Deadly diagnosis

Click to enlarge

The fine print: Cancer staging data Cancer Care Ontario (CCO) provided The Spectator exclusively with data for the stage of cancer at time of diagnosis for the amalgamated City of Hamilton for the years 2010 through 2013. Not all cancer diagnoses were captured, including those where the stage was unknown or not recorded. The data was broken into Stages I through IV.

The data was provided at the level of census tracts in Hamilton. Census tracts are the units of geography used by Statistics Canada to break cities into smaller chunks with populations generally in the range of 3,000 to 6,000 people. Statistics Canada uses census tracts to measure a wide variety of social, economic and health variables within urban regions of Canada. In this case, CCO broke Hamilton into 95 census tracts.

Because of the potential for small sample sizes and privacy concerns, in part, the data was not differentiated by gender or specific cancer types.

CCO provided The Spectator with two types of data breakdowns for all census tracts. One breakdown provided the percentage of all of Hamilton's cancers by stage for each census tract. For example, a certain census tract might have been responsible for 1 per cent of all Stage I cancers in Hamilton, 2 per cent of all Stage II cancers, 0.5 per cent of all Stage III cancers and 0 per cent of all Stage IV cancers.

The other breakdown showed the percentage of cancers for that census tract that were diagnosed at each stage. In other words, a certain census tract might have had 25 per cent of its cancers diagnosed in Stage I, 50 per cent diagnosed at Stage II, 25 per cent diagnosed at Stage III and 0 per cent diagnosed at Stage IV.

These rates were then used to create maps showing the distribution of later-stage cancer diagnoses across the 95 census tracts. In this case, later-stage cancer is defined as those cancers diagnosed in either Stage III or IV. The maps were created by Patrick DeLuca of McMaster University who has collaborated extensively with The Spectator on past Code Red projects.

The stages of cancer A description of cancer stages from Cancer Research UK Stage I: The cancer is relatively small and contained within the organ it started in.

Stage II: The cancer has not started to spread into surrounding tissue but the tumour is larger than in Stage 1. Sometimes, Stage II means that cancer cells have spread into lymph nodes close to the tumour. This depends on the particular type of cancer.

Stage III: The cancer is larger. It may have started to spread into surrounding tissues and there are cancer cells in the lymph nodes in the area.

Stage IV: The cancer has spread from where it started to another body organ. This is also called secondary or metastatic cancer.

In addition to the four stages, oncologists also employ the so-called "TMN" staging system. TNM stands for tumour, node, metastasis. This system describes the size of the initial cancer (the primary tumour), whether the cancer has spread to the lymph nodes, and whether it has spread to a different part of the body (metastasized). The system uses numbers to describe the cancer.

T refers to the size of the cancer and how far it has spread into nearby tissue — it can be 1, 2, 3 or 4, with 1 being small and 4 large.

N refers to whether the cancer has spread to the lymph nodes — it can be between 0 (no lymph nodes containing cancer cells) and 3 (lots of lymph nodes containing cancer cells).

M refers to whether the cancer has spread to another part of the body — it can either be 0 (the cancer hasn't spread) or 1 (the cancer has spread).

So for example, a small cancer that has spread to the lymph nodes but not to anywhere else in the body may be T2 N1 M0. Or a more advanced cancer that has spread may be T4 N3 M1.

The author

Steve Buist is an award-winning investigative journalist and the creator of The Spectator’s highly acclaimed Code Red project, Steve Buist has won three National Newspaper Awards, been named Canada’s investigative journalist of the year three times and Ontario’s journalist of the year five times.