What's happening:

The routine quarterly announcement of financial performance from Target Corp. will come before the stock market opens Wednesday morning. This announcement will get more than the usual attention, however, because it is the first since the Minneapolis-based retailer revealed in December that its sales system had been compromised by hackers, resulting in the exposure of financial and personal information of tens of millions of customers.

The results will cover the months of November, December and January. Like many retailers, Target ends its reporting year in January rather than December in order to provide investors with an uninterrupted view of the holiday selling season.

What has the company said about the effect of the breach on results:

On January 10, Target told investors to expect a lower profit because news of the breach, which was announced Dec. 19, resulted in fewer shoppers coming to its stores. It told investors to expect a profit in the range of $1.20 to $1.30 per share. That was down from its previous guidance for a profit of $1.50 to $1.60 a share.

Target also said lowered its forecast for another important metric: comparable sales, a measurement of revenue that involves only stores that have been open at least a year and, thus, can be compared fairly. Target said to expect a comparable sales decline of 2.5% for the quarter. Before the breach, it guided investors to expect flat comparable sales. In the August-to-October quarter, Target's comparable sales rose 0.9%.

What else is impacting Target:

Before the data breach, the big issue for Target was the same facing all major retailers -- lackluster consumer spending. The company went into the holidays expecting flat sales and told investors in mid-December it was doing a little better than expected in part due to high demand for electronics. Then came the Dec. 19 announcement of the data breach and everything changed.

The company's other major issue has been its expansion into Canada, where it opened more than 100 stores last year. That business isn't yet profitable. Target said in November that its fourth-quarter profit would be reduced by 22 cents to 32 cents a share because of the Canadian operations. After the data breach, it said the Canadian operations would lower profit by about 45 cents a share.

What's the bottom line number to look for:

Taking the full impact of the data breach and Canadian loss into account, look for a profit figure of around 79 cents per share. Some optimistic analysts are forecasting a profit of 84 cents, while some pessimistic ones go as low as 69 cents.

How to find out more:

Target executives will discuss the results in a conference call with analysts at 9:30 a.m. tomorrow. Anyone can listen via the company's investor web site, www.target.com/investors. Look for the precise link under "upcoming events."

One other thing analysts and major investors will watch for:

Any indication Target executives give about the longer-term costs of the breach. The company could end up paying for the costs that banks have incurred, losses suffered by customers, if they materialize, as well as costs related to improving its data systems.

Christopher Horvers, analyst at JP Morgan, wrote on Tuesday: "We expect Target to provide detail of the known costs of the credit card breach including the cost to replace its own cards and update the credit card technology in its stores, in addition to fraud on REDcards. We may not yet learn the cost of other technology investments to update internal systems, what the incremental marketing spend will be to rebuild the brand, the cost of credit card monitoring that Target offered all customers after the breach, and the costs related to third parties such as the banks as numbers have yet to be finalized."